Pixeling in the Retrosphere

Creating a Comic Book on 1980s Hardware

Pixel Art Comic Project by Marin Balabanov

II. Journey Beneath the Metal

Assembling the Equipment

The first thing I wanted to get up and running was the actual hardware. I wanted to use a 16-bit computer from the 1980s. While 8-bit computers like the Commodore 64 and the Sinclair ZX Spectrum dominated the first half of the 80s, the most common platforms in the latter half were the Apple Macintosh, the Commodore Amiga, the Atari ST, and most widely used the IBM PC and its “clones.” The Apple Macintosh of the time was a black-and-white machine with a small screen. I did not want to go down that path. The Commodore Amiga was a powerful graphics machine with capabilities well ahead of its time. This did not provide the limitations I was seeking. An IBM PC running MS-DOS using the extremely limited EGA graphics was much too limited, so I was left with the Atari ST range of computers.

The original Atari ST was introduced in 1985. It was a 16-bit computer with a Motorola 68000 processor (a.k.a. Central Processing Unit or CPU). Atari built this machine to compete with the Apple Macintosh and the Commodore Amiga. It was priced well below the competition and offered a blend of both of its competitors' capabilities without fully exceeding any of them. Atari iterated on the basic technology of the ST from 1985 to 1991. After a number of successors that were not as successful as the Atari TT and the Atari Falcon, the company folded in the late 1990s.

The original Atari ST computer

Figure 1: The Atari 1040ST, the first revision of the original Atari ST
(Source: Wikipedia upload.wikimedia.org/wikipedia/commons/3/39/Atari_1040STf.jpg)

Choosing the System

This specific model is the Atari Mega STE which was introduced in 1991. It is largely based on the original Atari 520ST from 1985 with some minor improvements like a processor running at twice the clock speed (16MHz up from 8MHz), an extended color palette and a sound chip capable of digital Pulse Code Modulation (PCM) for higher quality sound samples. The regular Atari ST has a keyboard case, i.e. the whole computer is in the keyboard. The Mega STE had a more professional look, with the keyboard being separate from the system unit, much like IBM PCs at the time, but with a sleeker design.

The more advanced Mega STE, released in 1991

Figure 2: The Atari Mega STE
(Source: archiwum.allegro.pl/oferta/atari-mega-ste-i7309896659.html )

The case of the system unit has a built-in 3.5" disk drive and a fan. This adds annoying background noise during operation, but the fan makes the computer usable over extended periods of time by preventing it from overheating. The case also has room for a hard disk that is attached through the internal SCSI bus.

I purchased my Mega STE from the retro computer retailer Atari Fachmarkt in Germany for around €300. I decided to use a retailer instead of eBay because I needed a machine that worked reliably and had been serviced professionally. The device was in a great working condition. The retailer had cleaned it and replaced the electrolytic capacitors that are prone to leakage after decades of use. The Atari no longer had the original keyboard but had a replacement unit from a previous line called the Mega ST (without the "E"). The machine was expanded to its maximum of 4MB RAM and had the original spinning hard disk with 20MB in it.

Wishlist of Extended Capabilities

So now that I had the computer, I wanted to extend its capabilities. First of all, I wanted to be able to use a modern LCD. While I did still own a CRT (Cathode Ray Tube) screen, the model I had could not cope with the 14.6KHz horizontal sync signal from the Atari. More importantly, using a CRT at these low frequencies (50/60Hz vertical refresh) for extended periods of time is not something I wanted to endure. I wanted to use the Atari STE to a much more eye-friendly LCD screen. I not only needed the right cable, but also a way to up-convert the low horizontal sync signal to be accepted by modern day displays.

The next hardware feature I wanted to change was the 3.5" disk drive. The drive the machine came with was the original double density (DD) 720KB version. They do have an MS-DOS compatible disk format, but they are unreliable when writing to the more commonly available high density (HD) floppy disks that were designed to hold 1.44MB. I decided to completely do away with the disk drive and replace it with a storage medium that I could use with my MacBook Pro. I wanted to be able to exchange files between the Atari and my modern working machine.

The built-in hard disk was slow and unreliable. I doubt that I will ever make full use of its 20MB storage, but I also did not want to be limited by the small storage space if I ever did. So, I decided the hard disk had to go.

The last three extensions I wanted to make was to use a modern-day mouse instead of the original Atari ST mouse that had a rolling ball with pins tracking it. These mice did not endure the decades well and are practically unusable today unless they were kept in the most pristine condition. I wanted to replace the mouse with a more modern one. Perhaps, I might not even use the mouse to draw on the Atari, but rather, use a graphics tablet. The first good consumer models started to become widely available at the time of the Atari's release. And finally, I wanted to try networking the Atari Mega STE to my MacBook Pro for a more efficient mode of data exchange.

Making the Screen Upgrade

Finding the right cable to attach the unit to a more modern TV was not as difficult as I had imagined. At the time of the Atari's release the then new SCART TV port had been introduced. In essence, this was a composite video output in more or less square port design. This standard was introduced in France in 1976 and it used a 21-pin connector. Also, the port design was starting to be generally adopted by European TV manufacturers in Western Europe as of 1987. There was a large aftermarket supply of Atari RGB to SCART cables. I purchased a working cable reasonably on eBay. (More about the SCART standard here: http://fr.meric.free.fr/Articles/articlesba/stsurtvplat/Scart/BS_EN_50049-1%20Peritelevision%20connector.pdf )

The LG LCD display that I wanted to use with the Atari STE still had a SCART port on the back. The issue was again the wildly outdated 14.6KHz horizontal sync signal provided by the Atari. Even when connected to the LG LCD display, the screen remained blank because the signal was too weak. I researched a solution and it quickly became apparent that I needed a video scaler.

According to Wikipedia "a video scaler or upscaler is a system which converts video signals from one display resolution to another; typically, scalers are used to convert a signal from a lower resolution (such as 480p standard definition) to a higher resolution (such as 1080i high definition), a process known as "upconversion" or "upscaling" ...So much for Wikipedia.

According to the no more unreliable retro computing forums on the web, there are dozens of cheap video scalers, but there was only one true HDMI upscaler worth using: the legendary Micomsoft Framemeister from Japan. This device had gained popularity in the retro gaming scene over the past decades. Particularly gamers who wanted to use their Nintendo Famicom video game systems and their Sega Megadrives from the 1980s swore by the Framemeister. The device takes the original low fidelity signal from the old hardware, runs it through a signal processor and upconverts it to an HD signal and outputs it to the standard HDMI port that can be used with most modern-day LCD or OLED HD TV and monitor. And the Framemeister does the work with a minimal processing lag.

The Framemeister HDMI upscaler

Figure 3: Micomsoft XRGB mini Framemeister HDMI Scaler
(Source: eurogamer.de/articles/2015-08-20-micomsoft-xrgb-mini-framemeister-hdmi-scaler-test )

I knew that I had to get a Framemeister. Unfortunately, after a decade of production and a number of revisions, the manufacturer had ceased production of this dedicated piece of specialty hardware. The prices on eBay had skyrocketed. But I did not want to be deterred by banal setbacks as ridiculous prices, so with tears in my eyes I shelled out close to €360 to purchase and import a Micomsorft xRGB Framemeister Mini from Japan.

Weeks later the Framemeister arrived. This HDMI upscaler had a large assortment of ports, but to my dismay no SCART port. This should have come as no surprise, as the strictly European SCART port would be of a low priority in a device manufactured for the Japanese market where the small, roundly S-Video port had found a much wider adoption instead. I bought a converter from SCART to S-Video from a local chain of electronics retailers and could finally attach the Atari MEGA STE to the LG LCD display. The very low-fi signal from the Atari was converted and up scaled to a full HD display. Now, obviously the resolution here is still the Atari's original low resolution of 320 x 200 but it can be displayed in full quality on an HD screen. The picture on the LCD screen was beautifully crisp with consistent colors. The Framemeister was definitely worth it.

The Invoice of the Framemeister

Figure 4: The painful invoice for the Framemeister order from Solaris in Japan.

Yes, the amount is approx. €380 with shipping
(Source: Marin Balabanov)

New Floppy Disk Storage

The second extension that I've added is a replacement for the broken 3.5" floppy drive. This is an HxC floppy drive emulator. It is pin compatible to the old floppy drives from the day and replaces the floppy with an SD card. The reason why it is called a floppy emulator is because it pretends to be a regular floppy disk drive.

The card cannot be read as it would on a modern machine, but rather, it contains floppy images, i.e. exact captures of full floppy disks stored as individual files on the SD card. These captures of the floppy's content, these floppy images, are treated just like normal floppy disks by the host computer in this case the Atari ST. An SD card can hold thousands of images. Each individual image still only holds around 720KB, but effectively, the SD HxC is capable of providing thousands of diskettes to choose from when the machine boots up.

I purchased this from lotarek.pl, a retro computing enthusiast site in Poland.

HxC Floppy Disk Emulator

Figure 5: The HxC Floppy Disk Emulator
(Source: lotharek.pl/productdetail.php?id=28 )

Hard Disk Replacement

I decided to replace the unreliable hard disk with a so-called UltraSatan. This device houses two SD cards and provides a standard SATA hard disk interface and a converter to the SCSI interface needed in the Atari Mega STE. The name is derived from the SATA interface and is not related to satanism, but rather to the hobbyist scene's sense of "cool."

The UltraSatan uses the SD cards as virtual hard drives, so the computer "sees" them as hard disk partitions. The Atari STE being created to legacy specifications cannot handle the massive SD card storage available nowadays. Even comparatively "tiny" SD cards with "only" 2GB are too large for the computer to recognize them as a whole. There is a solution to that: I partitioned each SD card into multiple partitions that are no larger than 512MB. So, I ended up with eight partitions in total over the two SD cards (with 2GB each).

The UltraSatan is simply attached to the Atari's external hard disk port as an external device or to the internal SCSI/ACSI port as an internal device with an appropriate SCSI terminator. I decided to use the external option because I did not have the needed SCSI terminator and I also thought it might be useful to be able to access the SD cards easily without opening the case.

This device was also available at the lotharek.pl retro hardware online shop. I purchased it for around 90 Euros and added a couple of low-capacity SD cards to it.

I copied a large assortment of applications, games, and demos onto the SD cards. Among them were graphics programs such as DEGAS, Cyber Studio CAD 3D, Cyberpaint NEOChrome, Deluxe Paint, and many others.

UltraSatan Hard Disk Emulator

Figure 6: The cased version of the UltraSatan
(Source: lotharek.pl/productdetail.php?id=48 )

Input Galore

To replace the mouse with a more modern mouse, I used a converter from PS/2 to 9-pin D-connector. The 9-pin D-connector is the Atari standard joystick interface that was also used for the mouse. The PC-standard PS/2 port was introduced by IBM with its PS/2 line of computers in the late 1980s. Before the wide adoption of the USB port, the PS/2 port became a de facto standard for keyboards and mice on MS-DOS/Windows machines. The PS/2 Converter enables a much more modern PS/2 optical mouse to be attached to the Atari. The PS/2 connector is not exactly the most modern interface because that connector started to deprecate around 2004/2005, but I can nevertheless use a much more modern mouse than the original Atari model. The Atari's mouse port (9-pin D-connector) is located underneath the keyboard. The rather long PS/2 converter just about fits in the small area, while leaving enough room to attach the actual mouse cable. These interfaces are custom made and thus quite rare, I was lucky to stumble upon a PS/2 adapter at the Atari Fachmarkt, before the shop closed.

PS/2 Mouse Adapter

Figure 7: The Adapter for a PS/2 mouse for the Atari ST (Source: Marin Balabanov)

The next input device I wanted to try was a graphics tablet called the ArtPad II. It is attached to the computer using the serial port and requires drivers to work with the Atari. Unfortunately, I never could find drivers for the art pad, given that this is a very old graphics tablet that was a niche product for the Atari ST. This was not a critical component, so I let it be, and instead used the mouse to draw. I bought the ArtPad II on eBay.

ArtPad II Graphics Tablet

Figure 8: The ArtPad II
(Source: interface-experience.org/objects/wacom-artpad-ii/ )

Finally, I added a Local Area Networking (LAN) cartridge called NetUSBee Mini to the Atari. Originally, I had intended to use it to exchange information with another computer using a LAN cable. Yet, the available options with the two different SD card solutions I had installed proved to be sufficient. The slow transfer speeds and the fussy connection of the LAN cartridge made it redundant and I never ended up using it beyond the initial installation phase.

This product I also purchased from lotharek.pl, fine purveyors of retro hardware.


Figure 9: The NetUSBee Mini
(Source: lotharek.pl/productdetail.php?id=46 )

The Upgrade Procedure

Now that I've reviewed the end state of the Atari Mega STE with all of the newly expanded hardware capabilities, I'll outline the upgrade process.

I took apart the Atari Mega STE by detaching all cables and unscrewing the bottom of the system unit. I detached all the cables leading to the floppy and to the LEDs for drive activity and power. This gave me full access to the main board of the Atari.

Upgrade Step 1

Upgrade Step 2

Upgrade Step 3

Figure 10: Taking apart the Mega STE's case to replace the internal floppy disk drive (Source: Marin Balabanov)

First, I upgraded the floppy disk, the hard drive, and the fan. The floppy drive was a drop-in replacement for the SD HxC drive. I simply unscrewed the floppy drive and then replaced it with the HxC. I had to make sure that the power cable and the floppy connectors are attached in the correct orientation and that the DIP switches on the HxC drive are set to the correct configuration. Due to the difference in size, some screws were left over. I removed the hard drive, but did not replace it with the UltraSatan, because I had opted to use it as an external device, leaving the internal SCSI port vacant for future use. I attached the power and the monitor to the Atari to test the HxC floppy emulator. It would have been a bit of a chore if I had reassembled the computer only to find out that the drive was non-functional, thus compelling me to disassemble everything once more to fix it.

Upgrade Step 4

Figure 11: The installed HxC Floppy Drive Emulator (Source: Marin Balabanov)

Once I was sure the device worked, I needed to provide the opening in the case for me to insert an SD card into the HxC once the case is closed. I had to break open part of the case because the HxC needs a bit more space than a regular floppy drive. I filed away the excess edges until there was sufficient room for the HxC drive

The next step of the operation was the most complex. I wanted to replace the old fan with a new Noctua NF-a6c25 FLX I got on Amazon. The old fan was quite loud, which was not unusual for the time, but technology has moved on since then and the new fan of exactly the same size, draws less power and is much quieter. In fact, I'd go so far that it is so quiet as to be being unnoticeable during regular operations.

Upgrade Step 5

Upgrade Step 6

Figure 12: Replacing the fan with a new low-noise fan from Noctua

I found the appropriate installation instructions on retro fan DBug's blog: blog.defence-force.org/index.php?page=articles&ref=ART45

To remove the fan, I needed to detach the power supply and remove it from the case. This was a bit fiddly but allowed me to unplug the old fan. Once that was done, I replaced it with the new fan in the same position. I gave the motherboard a final clean up with some compressed air and then launched attached the power supply and screwed it in place. Before reassembling the case, I gave it a final test run to see if the machine draws power as intended. Once that was clear, I meticulously reassembled the computer again.

Upgrade Step 7

Upgrade Step 8

Figure 13: The Framemeister mini xRGB attached to the Atari Mega STE with all necessary adapters (Source: Marin Balabanov)

The final result of all the travails is an Atari Mega STE with 4 MB of RAM, eight virtual hard drives extending across two SD cards on an Ultra Satan, a HxC floppy drive emulator for data exchange, and a network cartridge for LAN.

Upgrade Step 9

Upgrade Step 10

Figure 14: The "new" PS/2 mouse (left), the PS/2 adapter fitted into the external keyboard (right)

The machine is connected to an LG HD LCD screen display using a Framemeister. And the mouse is an optical PS/2 mouse connected using an adapter for the 9-pin D-Connector.

Now that the hardware is prepared and ready for use, we can move on to the software.

Upgrade Step 11

Upgrade Step 12

Figure 15: The UltraSatan with the two prepared SD cards sitting on top of the Framemeister (left), and the ArtPad II attached to the Atari STE (right)

Upgrade Step 13

Figure 16: The finished upgraded Atari Mega STE with all Peripherals

Why not use an emulator or an FPGA?

The big question in this project is likely why I insist on using original hardware and not simply use emulation on a modern machine?

Here, I will have to take a step back to explain. I understand that it seems ridiculous to upgrade a thirty year old computer with current day storage devices (SD cards), a newer input device (PS/2 mouse) and a modern day display (HD LCD), instead of simply using a new computer which comes out of the box with these features and then simply run an emulator like Hatari (hatari.tuxfamily.org), an SDL-based Atari ST/E and Falcon emulator on MacOS, Linux or Windows, or the emulator STeem (sourceforge.net/projects/steemsse/) on Windows. I understand that it seems silly to use the old hardware, but only have little of the charm, e.g. by attaching a CRT (cathode ray tube) display and using an LCD (liquid crystal display) instead. Software emulators running on today's vastly more powerful hardware are not even bound to the same performance limitations of the original retro hardware. They can speed up the emulation and pretend to be much faster machines that could ever have been built from the old components.


Figure 17: The MiST FPGA model with MIDI ports
(Source: picclick.fr/MiST-13-FPGA-CLONE-COMPUTER-173823275503.html#&gid=1&pid=2 )

To make things even more convoluted, I could use modern hardware that does not use emulation. MiST is an FPGA, i.e. a Field Programmable Gate Array. This is a custom designed integrated circuit that can be configured (field-programmed) to act and behave exactly like the original Atari ST hardware. Potentially, an FPGA can be much more compatible and cycle-accurate than a software emulator even on the fastest hardware. I own the MiST FPGA which as the name indicates is an FPGA originally designed to act as an Amiga and ST (hence amMiga ST), though there are a multitude of so-called cores (hardware abstractions that turn the FPGA into the processor and chips of the original hardware) for a number of retro systems including the Commodore 64, the Sinclair ZX Spectrum and QL, the Sega Master System, the original Nintendo Entertainment System, and many more 8-bit and 16-bit systems.

Again, I return to the question: Why use the original hardware?

First of all, the available Atari ST/E emulators no matter how accurate and compatible are optimized for the vast games library available for the machine. Graphics applications do run perfectly fine on Hatari and STeem, but the devil is in the details. When drawing every single pixel using the mouse, the tiny timing differences become apparent. The way the old mouse works, as finicky as it is, introduces an ever so slight lag or erratic behaviour that makes it exceedingly cumbersome to draw the total of 640,000 pixels over five pages (where each page is composed of two screens at 320 x 200).

And I must say, that the mouse behaviour is slightly off in emulation, even though it is not noticeable when playing games. Though it may be counterintuitive, it is also an issue using an FPGA.


Figure 18: The MiSTer FPGA
(Source: manuferhi.com/p/mister-fpga )

Second of all, I want to be as close to the original experience using the original hardware as necessary, but not suffer from the unreliability that the spinning disk drives, and old CRT might have by now.

I don't want to lose my work because of a data loss due to a failing disk drive or hard disk. While I love the aesthetic of pixel art on a CRT where the scanlines meld together, I don't want to risk the project because a CRT starts breaking due to old age. The Atari ST/E provided a notoriously bad video signal. In the color display modes, its vertical frequency in the European PAL region was 50Hz and 60Hz in the US NTSC region. But it's horizontal scan rate was a paltry 14.4Hz, which made the original Atari ST unusable with a VGA monitor of the time, unless it was a rare Multisync model. Using a CRT for extended periods of time is also not feasible because it tires the eyes. We might have put up with this thirty years ago, but if using a CRT can be avoided today then damn well should be.

Finally, the upgraded retro setup does in fact introduce tiny discrepancies and irritations. I did not use the original Atari ST mouse with the ball for movement tracking, opting to go with a late 90s PC mouse that used infrared to track movement across a surface. The PS/2 to DB8 adapter I used to attach the newer input device does an admirable job, but the PC mouse communicates movements slightly faster than the original one. The IR sensor is much more sensitive than a moving ball with two rolling pins, it samples the mouse movements at 1200dpi as opposed to the original approx. 200dpi of the Atari mouse. This makes the mouse pointer move faster than it should. I managed to mitigate this by using a small but useful application that was originally designed to accelerate mouse movements. Instead of its intended purpose, I used it to slow down the mouse pointer speed sufficiently to reduce the movement to the original speed.

There is one more thing that speaks for the use of original hardware: The build quality. Some of the devices from the 1980s and early 1990s were much more solid and reliable than nowadays devices. This was not only due to "things simply being better back in the day." All computers had to comply with much stricter radio interference standards, and as a result, needed to have bulkier shielding which made them heavier. Particularly the predominant desktop computers of the day were less prone to breakage than today's mobile devices like notebooks, tablets and smartphones by virtue of being seldomly moved.

As long as the original hardware is available and functional, and as long as it can be made to interface with modern day storage and display devices it will always be the more authentic experience and work as originally intended.

The upgraded Mega STE

Figure 19: Another view of the fully equipped and upgraded Atari Mega STE, ready to create pixel art comics (Source: Marin Balabanov)