retrocomputing

Mac OS 7.1 CZ, Serial Cable and File Share

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I’ve installed a new “hard disk” in my PowerBook 100 a few months ago. However, until now, there was no time to install an operating system other than the primitive System 6.0.8E that I used in the floppy-only mode. My goal was to have a Czech version that would allow me to read and write documents with our unique letters like Ř/ř. With a help of my friend, I got the floppy images of Mac OS 7.1 CZ and was able to copy them on real floppies (using my modern iBook G4 and a generic USB drive).

Working with old Macs can be painful due to use of file metadata (called resource forks) that can be lost very easily. Old Mac apps insist on this metadata and refuse to open a file if metadata is lost. Having a modern Mac is always handy to prevent these situations.

I don’t have a Mac serial cable. However, I recently bought two adapters for the conversion from Mac/SGI 8-pin mini-DIN to PC DB9. Connecting these adapters to a standard null-modem on both sides worked well and I was able to copy programs and documents from another old Mac. I’ve also managed copying files from/to a modern Windows PC. I pack the files into a ZIP file (to preserve resource forks) inside a Mac emulator and copy it using ZMODEM.

Insignia SoftWindows 95

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PC compatibility was a big thing for UNIX workstation manufacturers in the 80s and 90s. It started with x86/DOS emulators for text-only applications and later evolved in products like SoftWindows 95. This is a full x86 emulator with pre-installed and pre-configured Windows 95 in it and Insignia ported the emulator for non-PC platforms including IRIX, Solaris, HP-UX, MacOS, NeXT and other systems.

I have to say that installing the emulator on SGI IRIX is way easier than I expected. Just insert the installation CD, run the IRIX Software Manager, confirm the installation and that’s it. The first start of the emulator installs the Windows 95 by copying all the files on the virtual hard disk and deploying device drivers. It took maybe three minutes and didn’t require any user interaction.

Windows is preconfigured to see all UNIX folders as network drives, network is configured so you can immediately go on-line with Internet Explorer 3.0 or access SMB file shares. Mouse emulation works the same way as with modern virtualization software so you can seamlessly move the cursor between Windows 95 and IRIX windows. It also changes the Windows 95 screen resolution immediately after resizing the emulator window.

On the other side, games are not playable on my 400-MHz MIPS R12000. There are strange lags every few seconds (although between them, fps is similar to early Pentium systems). Office software runs ok and the only major limitation is in supporting up to 8-bit display modes (no more than 256 colors).

ATI Graphics Solution rev 3 and monochrome ADI DM-14 (1985-6)

My Vienna 286 (1987) has finally got a monochrome MDA monitor so I can put back the original graphics card (ATI Graphic Solution rev 3). This first ATI chip (CW16800-A) has functions necessary to drive CGA and MDA/Hercules modes, so you can connect both types of monitors although the card is very small. In fact, I was thinking that it was something much newer than the rest of the system but that was not true. ATI implemented most of the circuits in a big GAL (Gate Array Logic, maybe that’s why they were called Array Technologies, Inc.) which allowed them to make the card very compact.

I’ve started with MCGA graphics in 1989 and then with SVGA graphics in 1990. I had never had an opportunity to play with Hercules graphics modes, so I was extremely curious. Using high-resolution text-mode applications in an MDA mode (IBM Monochrome Display Adapter) is a pleasure on this long-persistence screen. Especially when you consider that the same experience was possible since day one with IBM 5150 PC in 1981.

Hercules Graphics Adapter (HGC) used almost the same signal timing as MDA and added a graphics mode where each pixel (720×348) could be changed independently. This allowed business applications to use high-resolution monochrome graphics (black/white) and the card became quite popular (ATI was not the only company making HGC clones).

HGC mode is not the best choice for gaming. Although a lot of games supported the HGC mode, they usually used a simple hack with CGA data. These were the typical approaches:

  • Prince of Persia: 320×200 CGA graphics is horizontally stretched to 640 pixels where each two adjacent pixels are used for dithering (4 shades -> 2 shades). There is no vertical expansion used in the game. The developers just put the 200-row graphics in the center of the 348-row screen.
  • Stunts improved the approach used in Prince of Persia. There is always a black row after two standard rows, so the screen is expanded to 300 rows. I’m surprised that it doesn’t look bad at all on the real CRT.
  • F-15 Strike Eagle tries to expand the graphics to the whole screen area. The vertical expansion is done by doubling every second row.
  • Microsoft Flight Simulator 3.0 looks great because it works with vector graphics. Thus, it can use the full HGC resolution. The result is better than with CGA with exception of the 16-color composite CGA output.

Atari Stacy And a New Display

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You can still buy a new white-on-blue LCD for Atari Stacy (a 30 years old system). The reason is simple – the same screen is used in multiple medical/industrial devices. The result is better than backlight replacement we did on a different unit although the new screen is glossier. Now we have two fully working machines.

I don’t have much experience with 16-bit Atari computers so I was quite surprised that the system has also some tricks to get more than 16 colors our of the machine. Albeit not as useful as the HAM mode on Amiga, this is still impressive.

CP/M running on Sinclair ZX Spectrum +3

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Unlike previous ZX Spectrum computers, +3 is equipped with an internal 3-inch floppy drive (compatible with Amstrad computers) and it is fully capable of running CP/M. The system runs snappier and more responsive than Commodore 128 in the CP/M mode but there are two caveats. Multiple keys are missing in the crippled keyboard layout and these are replaced with cumbersome keyboard shortcuts. This can be especially annoying when working with spreadsheets.

Another issue comes from the fact that the video circuit works in a resolution of 256×192 so it cannot handle the standard 80×24 text-mode typical for CP/M machines. The computer normally displays only 32 characters per row which would not be enough for any CP/M program. The +3 version of CP/M therefore uses a reduced font resolution with just 5×8 pixels for each character (including space between characters). Such font allows to display 51×24 characters and that’s the default text mode when +3 is booted in CP/M.

Of course not all programs work correctly with the reduced screen size so there is a program called SET24x80.COM. It provides a virtual 80×24 screen and you can quickly switch between displaying the first 51 columns or last 51 columns of the screen using a keystroke.

Bright Text on 1-bit Displays

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XT-class Toshiba laptops started to use “double-scan CGA” displays with a resolution of 640×400 in the late 80s. This allowed for better graphics and much sharper text in comparison with ordinary CGA solutions. However, the LCDs which Toshiba used worked only in 1-bit mode so there were no shades of grey (blue). Lower resolutions in graphics emulated (four) colors using 2×2 patterns. The text mode, on the other side, emulated the intensity bit (bright text) using bolt characters.

Toshiba experimented a lot with hi-res fonts in ROM and I’m not pleased with the results. Standard (thin) font is hard to read and not visually appealing. Fortunately, it is possible at least to swap the bold and standard fonts using a keyboard shortcut. It is strange that the highlighted characters are in fact less readable then but overall experience is still better than with the default setup.

Sun Ultra 5 Workstation (1998)

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After the introduction of Windows NT and later introduction of Intel Pentium Pro, the PC platform slowly became a big threat for UNIX workstation manufacturers. Most of them disappeared from the market. Some still exist but they don’t make UNIX workstations anymore.

Sun was well aware of the issue and introduced low-cost UNIX workstations based on their own UltraSPARC CPUs. Unlike other models, these were made mostly from off-the-shelf PC components. There are industry standard EDO RAM modules (with ECC) and the frame buffer is in fact an ordinary $40 ATI Rage Pro PCI video chip. All on-board devices communicate over the standard PCI bus and mass storage devices are connected to an IDE controller instead of more common SCSI (at the time).

On the other hand, there is a full-blown UltraSPARC II CPU similar to the ones in Sun’s high-end workstations. There were two configurations available at the beginning. The lower-end one with 270-MHz CPU has 256 KB of external (L2) cache. Its integer performance is on par with similarly clocked Pentium II and the floating point performance is up to 25% higher (comparable with 290-MHz DEC Alpha). The 333-MHz configuration has 2 MB of external cache which can double the performance in certain types of tasks (+80% in SPECfp95).

Let’s put Ultra 5 in the 1998’s workstation perspective. The main target for this machine was “technical computing”. With the price starting below $5.000, Ultra 5 was the easiest way to get a new UNIX workstation. Low-spec SGI O2 workstations cost about $8.000 and their R5000 CPUs were much slower. An R10000-based O2 would be comparable in terms of computational performance. However, such machine was not available under $15.000. To be fair, SGI O2 can handle 3D in hardware (triangle setup, Z-buffer, texturing) and, according to my testing, even the configuration with 180-MHz R5000 (true-color RGB888) is 3-3.5x faster in OpenGL tasks than 270-MHz Ultra 5 (256-color-only mode with RGB332).

Ultra 5 utilizes its on-board ATI Rage Pro chip only for simple 2D acceleration (BitBlt) and the driver made by Sun ignores all video and 3D capabilities of the chip. Solaris doesn’t support the 16-bit color mode (only 8, 24 and 24+8 are supported) which is the only one where ATI’s chip can handle 3D acceleration. Although the chip didn’t shine in image (3D) image quality, its raw performance in professional OpenGL applications was similar to the SGI O2 integrated video (tested under Windows NT). There is no excuse for not using the video acceleration. Rage Pro was pretty good in video (filtered scaling, color conversions,…) and an average mid-end office PC with this chip (on-board) could easily outperform Ultra 5 in MPEG full-screen playbacks. 320×200@30fps video can be played back only in 1:1 mode. If the video is displayed in full-screen, frame rate drops to 1-2 fps.

This is my first experience with Sun workstations (apart from using Sun Ray thin clients at college) and I’m not very impressed. Basic administration is much more difficult than in IRIX or HP-UX (these two have nice GUI/TUI programs for this purpose). The keyboard has useless additional keys and the mouse cursor is refreshed only about 20x per second. The CPU performance was good at the time of introduction but everything else was not competitive in comparison with $4.000 Pentium II PCs. When it comes to multimedia support, even Linux distros from the 1998 were not worse than Solaris.

*) Last photos show that (unlike other UNIX workstations) Ultra 5 cannot handle multiple 8-bit palettes simultaneously. A whole palette is set according to needs of the window that is active, which results in psychedelic color effects. On the contrary, Windows 9x and NT were ready for dealing with single-palette video chips by reserving about 20 colors for GUI. These colors could not be changed if the active application was not in the full-screen mode.

Excel 2.0 (1987)

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Excel 2.0 running on Windows 2.0. This is so 1987… btw I modified the default color scheme in the system to make it less awkward by today’s standards.

HP-UX and Common Desktop Environment (CDE)

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The HP-UX installation was successfully finished with a large text over a half of the screen saying “FAILURE!” written in ASCII art. The whole process took about ten hours and after an automatic restart, the system booted up in the graphics environment.

The CDE GUI is not as intuitive as the one on SGI IRIX but I can live with it. I was more surprised that all color schemes (about 20) looked ugly as hell. The guys who were responsible for this were probably on LSD. Otherwise, I cannot understand the color combinations they created.

On the bright side – although the CPU runs only on 100MHz, the overall feeling of speed is better than on 200-MHz SGI O2. I have only a low-end graphics card capable of 1280×1024 in 256 colors (actually it can combine one 256-color palette for an active window and second 256-color palette for the rest), it is very fast and has no problems with refreshing windows while moving.

Btw the system cannot use audio in the CDE until the network is fully configured. It wouldn’t be a true UNIX without such jokes.