Posts tagged with vintage-computing

Revisiting my BBC Micro - display, speech & more

It’s been a while since I blogged about Revitalizing my BBC Micro. In that time I’ve performed a few upgrades you might find interesting…

Display requirements

As useful as the tiny Amstrad CRT was I wanted something bigger, brighter and sharper. LCD is terrible for retro systems with blurry scaling attempting to draw images designed to take advantage of CRTs. Emulator authors spend significant effort trying to mimic CRT effects for a true retro feel but the best option is just to use a CRT.

Most machines in the 80s and early 90s were designed for TV compatibility and so operated on a 15KHz horizontal refresh rate. The VGA CRT monitors people struggle to give away aren’t going to work as they start at 31.5KHz. British machines like mine also use the PAL (UK) video system rather than the NTSC (USA) system - ideally a display would handle both.

If you don’t need any VGA frequencies then a Sony PVM is the way to go. I also own an Amiga 1200 which is capable of some VGA modes so it would be nice to have one CRT for everything. Multi-sync monitors can do both but were rare back then and are even rarer now and the shipping cost on CRTs limits can be prohibitive.

Commodore 1942 CRT

Figuring out resistor levels and sync signalsLuckily for me a Commodore 1942 CRT “bi-sync” turned up on Craigslist just 15 minutes from my house for $50. It was designed for the later Amiga models so it does both 15KHz most of my machines can do and some VGA resolutions too. Perfect.

Connecting it to the BBC was a little trickier than I anticipated. That Amiga design means it expects the horizontal (HSYNC) and vertical sync (VSYNC) signals on two different pins to match the Amiga’s video port rather than the composite sync (CSYNC) all my RGB capable machines offer (Amiga excluded).

I briefly experimented with connecting the CSYNC to HSYNC, VSYNC and indeed both but failed failed to get a stable display. Digging in to the Motorola 6845 CRT controller chip that powers the Beeb reveals both VSYNC and HSYNC on pins 40 and 39 respectively. A quick snip of the RGB port’s unused 5v and sync pins let me repurpose them to HSYNC and VSYNC direct on the 6845. A stable but over-saturated picture was a welcome next step that didn’t involve me needing to create a SYNC splitting circuit (I did that later to connect with my Spectrum +3).

Running Citadel on the Commodore 1942The over-saturation is because the BBC Micro outputs either 0V or 5V - off or on - for each color. The Amiga monitor is analogue and accepts any amount of color between 0V and 0.7V. I read guides on calculating the voltage drop but it still looked saturated so I kept increasing resistor values until I found values that looked right.

The final result definitely made me smile. It looked better than the Microvitec CUB monitors our school had back in the day without losing the CRT appeal. Success!

Speech synthesis

Hearing Superior Software’s SPEECH package blurt out any phrase we cared to throw at it was a blown-away moment at school. I’ve always wondered what the official Acorn speech system was like especially as every time I open the case empty sockets IC98 and IC99 call out for the Texas Instruments TMS5220 speech processor and associated TMS6100 voice synthesis memory.

The TMS5220 chip was a successor to that in Speak & Spell, Bally/Midway pinball machines and some arcade games as is quite easy to come by. The TMS6100 was available in many variants and the BBC commissioned some of their own including one sampled by BBC news anchor Kenneth Kendall. This chip is rare now and the fact the TMS6100 is not a regular ROM means you can’t just burn a copy. Thankfully Simon Inns created an emulator which can run on an ATMega32U2 to provide a drop-in replacement!

I obtained a TMS5220 and pre-built TMS6100 emulator board from Mark Haysman at RetroClinic who I can thoroughly recommend! (My SMT soldering skills are not up to this)

After inserting the two chips and powering nothing looks different. This command sequence however provides a good test mechanism:

TMS5220 chip and TMS6100 emulator board

REPEAT : SOUND -1,GET,0,0 : UNTIL 0

Pressing any key on the keyboard will cause the machine to say aloud the letter although it has some odd ideas about what the symbols on the keyboard are.

I will be experimenting with this more as I dig through the capabilities in the manual as it isn’t as easy to use as Superior Software’s Speech! which lets you type things like:

*SPEECH
*SAY Hello there.
*SAY I've got a bad feeling about this.

ROM experiments

My school had a single copy of the Advanced User Guide so I felt privileged when the teacher would let me borrow it although on reflection I doubt anyone else wanted to. Page 395 cryptically teases:

Up to 16 paged ROMS are therefore catered for, 4 of which are on the main circuit board.

So the OS supports 16 ROMs but there are only physical sockets for 4 (IC52, IC88, IC100 and IC101). Typically BASIC and the disc filing system (DFS or ADFS) take two of them leaving just two usable ROM sockets for expansion.

The schematics reveal IC76 is the ROM Select Latch and is a 74LS163 with 4 output pins thus providing 16 possible combinations - one for each ROM you could use so both the OS and the circuitry can support what we need if we could physically get the ROMs wired in.

The Beeb supports either 8K (2764) or 16K (27128) ROMs and EPROMs. Later 64KB (27512) chips became available which are almost pin-compatible with the 27128 except:

A collection of ROMs and an EPROM

27512 Pin 27127
A15 1 Vpp
A14 27 /PGM
/OE 22 /OE, Vpp

The /PGM and Vpp lines are for writing - an EPROM programmer will care about these but our Beeb won’t.

The A14 and A15 lines are the address lines for accessing the higher memory. With them both low the chip just acts like a regular 16K (27128) chip. With A14 high it looks to the next available 16K, with A15 high the next 16K and with A14 and A15 high the final 16K.

So what we can do here is combine four 16K ROM images into a single 64K file and flash it to our 27512 which is just what I did with my Signstek TL866A Universal USB programmer.

Now by connecting A14 and A15 to the IC76 address line C and D outputs we have effectively given whatever socket we connect this two the ability to appear as four ROMs (this works only because a single ROM can be paged in at a time).

The final icing on the cake is that the Beeb sports a push-out section left of the keyboard (affectionately known as the “ash tray”) where a zero insertion force - ZIF socket - could be mounted to allow a ROM to be dropped in without needing to crack open the case (our school was definitely not wanting us to open the machines and yet only one machine had this upgrade installed).

Now I just need to figure out how to mount this ZIF socket in the ash tray hole - there aren’t really any mounts. I suspect I’m going to need to make a PCB of some sort and put legs on it.

Building your own

Parts list

  • 28-pin ZIF socket
  • 28-pin DIP socket 0.6” wide
  • length of 28-way ribbon cable
  • 2.54mm header pins (you just need two)
  • 2x female-to-female jumper wires

Creating the cable

  1. Wire all pins from ZIF to DIP except for 1 & 27
  2. Solder two header pins to 11 & 12 on IC76
  3. Jumper ZIF pin 1 to 11 on IC76
  4. Jumper ZIF pin 27 to 12 on IC76

Now insert a 27512 ROM flashed with four BBC ROMs of your choice, power up and type *HELP or *ROMS to see the images ready.

Also check out alternatives for wiring up 64K ROMs or 32K SRAM chips from J.G. Harston

Second processor via a Pi Zero

The Beeb has a bunch of expansion ports hidden underneath the machine - the most unusual one being the Tube expansion bus which allows for a 2nd processor by way of a FIFO buffers that facilitated message passing IPC for console, errors, data and system calls.

Acorn produced a number of expansions for Tube including:

  • 6502 second processor allowing well-behaved unmodified programs to run faster
  • Z80 for CP/M
  • 80286 for DOS or GEM

Raspberry Pi Zero with Level ShifterThese expansions are hard to come by as they don’t just feature the CPU but necessary additional isolation logic, memory and circuitry. David Banks developed PiTubeDirect to allow a Raspberry Pi to act as second processor plugged into the Tube port by way of a 5V to 3.3V level shifter - I got mine from Kjell Sundby

The Raspberry Pi 3 can emulate these old processors as crazy speeds - 274MHz for the 6502, 112MHz for the Z80, 63MHz for the 80286 and even a 59MHz ARM2 (Acorn were using the Beeb to work on ARM prototypes)

What piqued my interest was using the Raspberry Pi Zero though. It’s small enough to fit under the BBC Micro and remain plugged into the Tube port out of sight. Latency was a problem on the Zero given the lower ARM processor so they ported the CPU emulation core… to the GPU!

The 6502 emulation is reliable and enabled me to run the 6502 Second Processor Elite. I definitely need to try and get GEM running on it just for fun although it’s a little trickier to find suitable disk images for Z80 and 80286 co-processor stuff.

[)amien

Typography in bits: For a few pixels more

It’s been a while since I visited the bitmap fonts of old computers (see the bottom of the post for links) there are still some to look at!

There are a lot of subtle variations here as machines often used an off-the-shelf video chip and then made a few tweaks or had them slightly customized.

TRS-80 Color Computer & Dragon – custom MC6847 (1982)

TRS-80 system font

The initial model of the TRS 80 Color Computer – affectionately known as CoCo – as well as the UK’s Dragon 32 & 64 computers used the Motorola MC6847 character generator and so used the same embedded font.

Unusual characteristics

  • No lowercase
  • Serifs on B&D
  • Over-extended ‘7’
  • Asterisk is a diamond!
  • Square ‘O’
  • Cute ‘@’
  • Thin ‘0?’
  • Tight counter on ‘4’
  • Unjoined strokes on ‘#’

Rationale

The font has some rough edges although the softer fuzzier look of a CRT TV almost certainly fuzzed those out like many home computer fonts at the time. The awful dark-green on light-green color scheme wasn’t helping though.

Influences

Has similar proportions and characters to much of the Apple ][ font but feels like they tried to make the characters more distinguished on low-quality TV’s hence the serifs on B & D and the differentiation between 0 and O.

Technical notes

Motorola actually offered custom versions of this ROM so it would have been entirely possible to have an alternative character set.

TRS-80 Color Computer v2+ (1985)

TRS-80 v2+ system font

The follow-up v2 model of the TRS 80 Color Computer – also known as the Tandy Color Computer used an enhanced Motorola MC6847T1 variant.

Unusual characteristics

  • Serifs on B&D, over-extended 7 as per v1
  • Ugly ‘@’
  • Very soft center bar on ‘3’
  • Tight counter on ‘4’
  • Tight top of ‘f’

Rationale

In general a much improved font over the v1 fixing the oddities with the asterisk, O, 0, 3, 4, S, ? and # as well as making the slashes straighter and reducing the boldness of comma, colon, semi-colon and apostrophe although the @ and 3 are worse than the previous version.

Influences

Based on the previous model however lower-case does have some resemblance to Apple and MSX. This may in fact be a custom version as the spec sheet for the T1 variant has bold versions of ,;:.’ glyphs, shorter descenders on y and g, more curvature on p and q, stronger curves on 369, tighter t, semi-broken #

Technical notes

You can identify CoCo2 models that have the lower-case as they say Tandy on the screen not TRS-80.

Tatung Einstein (1984)

Tatung Einstein system font

The Tatung Einstein TC-01 was a British Z80 based machine launched in the UK that never really took off with the public but had some success in the game development word being a compiler and debugger for other more popular Z80 systems thanks to its CP/M compatible OS and disk system (it came with the same oddball 3″ disks used on the Sinclair ZX Spectrum +3 and Amstrad CPC/PCW range)</a>.

Unusual characteristics

  • Odd missing pixels on ‘9S’
  • Little flourishes on ‘aq’
  • Massively tall ‘*’
  • Chunky joins on ‘Kv’
  • High counters and bowls on ‘gpqy’

Rationale

Given the 40 column mode the generous spacing in 32 column mode makes sense and the font isn’t too bad. Many of the negative unusual characteristics would be lost on a CRT.

Influences

It feels like the Sinclair Spectrum font with some horizontal width sacrifices.

Commodore 128 (1985)

Commodore 128 80-column font

While the follow-up to the Commodore 64 used the exact same font at boot – it had the same VIC-II video chip – switching it into 80-column mode reveals a new font with double-height pixels powered by the MOS 8563 VDC.

Unusual characteristics

  • ‘£’ aligned left not right, thin strokes
  • ‘Q’ fails to take advantage of descender
  • Cluttered redundant stroke on ‘7’
  • Rounded ‘<>’

Rationale

Quite a nice font with very little weirdness that probably looked good on any monitor at the time although TV’s probably struggled to display detail with such fine verticals on some letters.

Influences

Technical

Switching to 80 column mode could be achieved by using the keyboard or the GRAPHIC 5 command.

Texas Instruments TI-99/4A (TMS9918) (1985)

TI-99/4A system font

The follow-up v2 model of the TRS 80 Color Computer – also known as the Tandy Color Computer used an enhanced Motorola MC6847T1 variant.

Unusual characteristics

  • Lower case is small caps
  • Serifs on ‘BD’
  • Square ‘O’
  • Poor slope on ‘N’
  • Bar very tight on ‘G’

Rationale

The lower-case small caps feels quite awful and appears to be an attempt to avoid having to deal with descenders. Other fonts brought the bowl up a line and descenders look a little off instead although some machines like the Sinclair QL just left space for them.

Influences

Based on the previous model however lower-case does have some resemblance to Apple and MSX.

Oric Atmos (1983)

Oric Atmos system font

The follow-up v2 model of the TRS 80 Color Computer – also known as the Tandy Color Computer used an enhanced Motorola MC6847T1 variant.

Unusual characteristics

  • Bold ‘{}’
  • Vertical line on ‘^’
  • Awkward horizontal stroke on ‘k’
  • Square ‘mw’

Rationale

Not a bad choice although I suspect cheaper TV’s would struggle with the non-bold and tight spacing which is probably why they went with high-contrast black-and-white.

Influences

A complete copy of the Apple ][ system font with only a few tweaks to remove over-extension of 6 and 9 and un-bolding [ and ] but they forgot { and } weirdly. Additions of ^ and £ don’t quite fit right.

[)amien

Revitalizing a BBC Micro

BBC attached to Amstrad monitor and giant twin floppy drives Moving house means making possessions count so my collection of vintage computers has shrunk over the years and the bar keeps getting higher. Right now:

  1. It works – Test it, repair it or part with it. A wealth of online technical information makes this easier than ever.
  2. A small footprint – Eject unusable peripherals and accessories. Keep the essentials.
  3. Make it usable – Forget slow-loading tapes and corrupt disks, a fast loading is essential.
  4. Something special – It should either be collectible or one I have a connection with.

Recent casualties were my Apple ][e (no disks), Acorn ARM (wouldn’t boot) and Commodore VIC 20 (poor state). Next up is my Acorn BBC Micro B:

Physical inspection

My ‘Beeb’ is in good condition and works well although the case screws have long since disappeared (a common theme in my collection) and it needed a good clean. These older mechanical keyboards attract serious dust and dirt.

Schools were filled with BBCs in the 80s and I’ve written about the origins of this love affair before. I learned first BBC BASIC and then some 6502 assembly (mixing it with Basic) while at school. I later picked this machine up around 91 after seeing a local paper advertisement.

A giant twin 5.25″ drive housing system (shown above) contained my one still-functional floppy drive. I want to be able to read some physical disks but in keeping with the minimal footprint I transplanted the floppy drive into a 5.25″ externally powered CD-ROM enclosure. Big reduction.

The BBC Micro has a few video output options – UHF, composite over BNC and RGB over 6-pin DIN connector. By a staggering coincidence the pin out is identical to the Amstrad CPC so works directly my Amstrad monitor, no adapter cable required this time!

Replacement media, SD cards via GoSDC

BBC Micro with SD Card fitted

SD cards are my replacement storage of choice for vintage systems. I chose John Kortink’s GoSDC for the following reasons:

  1. Supports MMC, SD, SDHC up to 32GB
  2. Internally fits into a spare ROM socket
  3. Adds operating system commands for great integration
  4. Supports disc images, tape images and ROM images

Retro Isle comprehensively reviewed GoSDC in February (2015) and have a bunch of usage tips and tricks too.

Getting started with GoSDC

GoSDC installed inside a BBC Micro model BThe device plugs into a ROM slot but to make life easy you can give it access to a second one so it can patch the filing system. The docs are complex as they describe the many possibilities available. Here’s my setup that works well on a BBC Micro Model B (known as Option B in the docs):

  1. Remove Acorn DFS ROM
  2. Fit GoSDC in slot third from right
  3. Fit cable from GoSDC jumper (middle-left) to pin 6 up from bottom right
  4. You should be left with the Acorn OS ROMs in the ROM sockets to the left of GoSDC

Once fitted, slide in an SD card and power up your BBC and you should see the usual welcome screen. Then type *SDCINFO and see the results:


BBC Computer 32K

Acorn DFS

BASIC

>*SDCINFO

GoSDC (mbe) 1.05 (01 Sep 2014)

ROM slots : main 15, free 13

Flash ROM : S25FL007, 1024 KiB

Flash card : SDHC, 7580 MiB

Available areas
---------------
X :     416256 bytes
1 : 4294966784 bytes
2 : 3653238784 bytes

>

If you see ROM slots main and free with numbers your device is correctly controlling two slots and can patch the DFS for you. If not, check the adapter and cable.

If you see “GoSDC : No flash card inserted” check the card is securely in and power cycle the machine. If it still doesn’t recognize it try another card. Note: When switching card you will need to press CtrlBreak for the machine to recognize it.

The first time you use a card you’ll need to format it. The command and subsequent output should look like this:

>*SDCTOOL SDCFO
Formatting area ... done
Verifying format ... ok
Please hard-reset your machine now
>

If you have a card greater than 4GB then it will create 4GB areas which can be switched between with *SDCAREA number. I’d recommend switching to the additional areas, formatting and CtrlBreak after each before you put any software on it as this command will wipe it out again.

Finally you’ll need to tell GoSDC to provide a patched filing system like this:

*SDCCONFIG FSNR 1
*SDCCONFIG FSRM 13
*SDCRESET
  • 1 sets Acorn DFS on my machine although the docs says it should be 2
  • 13 should match the free ROM slot shown in *SDCINFO

If you mess up your ROM selection and are unable to type because of ‘No drive’ do not fear! Press caps-lock and break twice to get the prompt back and choose another.

Finding old software

One option is to image all your floppy discs to SD card but you are probably going to find that those discs are corrupted. Thirty year old floppy disks are not reliable.

Another option is to download old software online. This can be a grey area as the software is copyrighted but no longer sold and many authors are okay with allowing it (e.g. Ian Bell and David Braben of Elite fame). A great site that honors the wishes of authors can be found at the weirdly named Stairway to Hell.

The author of GoSDC supplies Windows scripts to download, unpack and write the files to disc which I took the liberty of porting to Bash so they could be used on Mac OS X and Linux.

Purely based on subjective childhood experiences…

  • Elite a 3D space trading game so good they recently Kickstarted Elite 4
  • Citadel one hundred screens of arcade adventure madness
  • Chuckie Egg quick platform dash with birds, ducks, eggs and platforms
  • Repton Boulderdash to the next level, try 1 or 3, Repton 2 is insanely hard
  • Granny’s Garden educational fun alas distribution is denied as they sell an iPad version

Using GoSDC

Once the card is loaded up with software the actual commands are simple:

*SDCLIST

Will list the contents although you’ll probably want to put a wildcard after it to limit it down. Remember CtrlShift pauses the screen on the BBC!

Then, to mount a disc you use *SDCDISC and provide the name to mount. You can also use wildcards here and it will pick up the first match. e.g.

*SDCDISC *Chuckie*

Once mounted hold down Shift and tap Break to boot the game (or educational title, right?)

A few other useful commands are:

*. List contents of a disc
*EXEC !BOOT What ShiftBreak actually does
CHAIN "filename" To LOAD and RUN a BASIC program from disc
*filename To execute machine code programs from disc

I put some BBC Micro tips and tricks together or you can can grab PDFs of pretty much every book created for the BBC Micro .

You can also see which discs are currently selected using *SDCDISC with no arguments. You’ll note you can mount a second disc and the command to do that is *SDCEXTRA with usage otherwise exactly like *SDCDISC.

GoSDC can do much more including imaging your real floppy discs and writing them back out so be sure to check out the comprehensive documentation which also includes how to upgrade the firmware (use another memory card as that process uses FAT no the GoSDC file system)

Out for Pi Day!

Pi Day (3/14/15 = 3.1415) was last weekend and my work put on a session for kids about how to program the Raspberry Pi using Scratch and a bread board (using CanaKits so we had a bread board, LEDs, switches, wires, resistors etc.).

The original Raspberry Pi was heavily inspired by the BBC Micro and even the name “Model B” took cues from the original. Few people also seem to realize that the manufacturer of the BBC Micro – Acorn – went on to create a processor for its sequel the Acorn RISC Machine or ARM for short. That’s right, the Pi is powered by an Acorn processor design (like most smartphones) so it made sense to bring it in.

Alas it was a hectic event with little time to show the machine. In fact just sitting there it popped a capacitor in a puff of smoke!

Power supply repair

Despite the noise and smoke the dying capacitor didn’t actually stop the machine working as it is part of the electromagnetic interference suppression not the power circuitry itself. Still, it should be repaired and I thought I may as well replace the other X2 film capacitor as they have been failing over the last 30 years.

BBC power supply with blown X2 capacitor BBC power supply with new X2 capacitors

I picked up a couple of RIFA PME 271 M capacitors – 100nf and 10nf – (with a matching pitch so they would fit correctly) from Mouser for less than $2 each plus shipping. Five minutes of de-soldering and soldering later and it was good as new!

[)amien

Typography in bits: Other English micros

I’ve been wanting to do a follow-up to the popular system fonts posts for some time and recent Hacker News and ArsTechnica traffic reminded me that I’m not the only one nostalgic for chunky pixel fonts of old.

This time I’m focusing on a handful British machines that were much less well known around the globe which – all seem to borrow heavily from other machines!

Sinclair QL (1984)

Sinclair QL system font in medium resolution

The short-lived Sinclair QL was Sir Clive’s attempt at getting into the business market but the corner cutting on the CPU (a Motorola 68008 – the 8-bit data bus version of the 68000) and storage (Microdrives consisting of loops of high-speed tape instead of disc) meant it wasn’t taken seriously. This was a shame as the operating system and software were advanced for its time.

Unusual characteristics

  • True descenders making the font effectively 9 pixels tall
  • Single story lower case ‘a’
  • Over-extended ‘7’
  • Squished lower-case ‘f’
  • Aligns braces and brackets to tightly wrap contents
  • Soft curves on ‘gil’
  • Unusual join on ‘k’

Rationale

A rather tidy condensed font very similar to those used on LCD displays still today. Almost certainly looked good on a monitor although perhaps not using the system default colors shown here. Almost certainly too hard to read on a TV at the time.

Influences

Has similar proportions and characters to much of the Apple ][ font but with various visual improvements such as on the 6,9,2,$ etc.

Memotech MTX512 (1984)

Memotech MTX512 system font in low resolution

Memotech were a peripheral maker who decided to get in on the action and produce their own machine in the 1984-1985 period that saw a lot of machines and failures. Despite some good specifications it never made a dent and its claim to fame being the computer in the movie Weird Science.

Unusual characteristics

  • Some quirky decisions especially in lower-case
  • Awful character alignment especially on ‘q’
  • Uneven descenders on ‘gy’
  • Mismatched ‘.,;:’
  • Weird serifs on ‘adu’

Rationale

This quirky font doesn’t look okay on low-quality TVs of the time with oddities lost in the blur. On sharper displays, it looks amateur and unfinished.

Influences

Despite some similarities in the upper-case to the Apple ][ font it doesn’t take many cues from anywhere else.

Amstrad PCW (1985)

Amstrad PCW system font in high resolution

Alan Sugar’s Amstrad didn’t waste any time after the CPC in going after the business market with a range of cheap machines for word processing and other general tasks. In the UK these machines could be found everywhere either paired up with Amstrad’s own daisywheel or dot-matrix printers.

Unusual characteristics

  • Pixels were actually rectangular (simulated here by doubling the vertical size)
  • Distinctive curves on ‘CGOQ’
  • ‘X’ looks like a different style because of high mid-point

Rationale

These machines came with their own monochrome monitors and were high resolution for consumers at the time. The font is not a bad choice and did allow for 90 columns of text but smarter alternatives existed in word processing programs such as Locoscript.

Influences

An almost direct copy of the Amstrad CPC font disguised by the double-height pixels. Actual changes are the 0 taking on the more oval shape, O and Q taking on the boxier shape and the apostrophe losing its slant.

The PCW was not alone in using an existing 8×8 font in a double-height manner. The Atari ST, Commodore Amiga, and Acorn Archimedes all used the same trick.

Acorn Archimedes/A series (1987)

Acorn Archimedes using double-height pixels

Acorn’s successor to the BBC Micro was a lovely piece of hardware with an all-new 32-bit RISC processor they developed dubbed ARM. While it did well in Acorn’s entrenched education markets it never found a foothold anywhere else. After various models they canceled their upcoming Phoebe workstation (yes, named after the Friends character) and would concentrate on thin-clients before abandoning that and focusing purely on processor design where they had immense success. The ARM design now powers almost all the smart phones on the market today.

Unusual characteristics

  • Pixels were actually rectangular (simulated here by doubling the vertical size)

Rationale

These machines came with Acorn’s color monitors and were capable of running VGA-like resolutions. The GUI on these machines really missed an opportunity here to use a specifically designed font and to add proportional text printing and take on the Mac. Instead, these used a scaled fixed-width font like the Amiga and ST despite being a couple of years late to that party. Proportional fonts were supported later.

Influences

Identical to the BBC font except for ‘^

SAM Coupé (1989)

SAM Coupé in high resolution

MGT were a third-party producer of expansion products for the Sinclair ZX Spectrum who bet their company on a Spectrum successor using VLSI technology that would ‘rival an Amiga’ at a fraction of the price. While the machine was impressive by 8-bit standards when it finally arrived somewhat late and more expensive than originally touted it failed to make a dent as the market went to the 16-bit machines and it took MGT down with it.

Unusual characteristics

  • Rather ugly ‘*’ asterisk
  • Inconsistent ‘.,;:’ set
  • Inconsistent ‘ and “

Rationale

A smart font that despite the various inconsistencies looked good on a quality display in both high and low-resolution modes.

Influences

Almost a direct copy of the Sinclair QL font. The upper-case are identical and a most lower case with some exceptions to squeeze the QL’s 9-pixel high font into 8 pixels. This is especially apparent in the over-extended 7, the slashes and the bracket alignments.

[)amien