Blog

CP/M and Input/Output Redirection

  • by

It is nice about CP/M how easily the input from a keyboard and output to a CRT can be redirected to another computer over a serial port using a single command.

Toshiba T1200XE (1990)

  • by

T1200XE belongs to the first generation of Toshiba portables equipped with 2.5-inch hard drives which allowed to make the machines smaller and lighter (3.6 kg). It has 12-MHz 80C286, at least 1 MB RAM (up to 5 MB) and a gorgeous 9,3-inch sidelit blue-and-white LCD. This LCD has a resolution of 640×400 and it is combined with a graphics chip that can utilize the full resolution for text and graphics (32 kB of video RAM).

“Grayscale” in 320×200 is emulated using 1-bit 2×2 patterns so the picture looks more like on Hercules cards emulating CGA. On the other side the screen is very sharp and blue text and backgrounds look cool.

SGI Visual Workstation 320 restoration #2

  • by

We’ve managed to replace all the capacitors on the SGI 320 logic board and it works. This was the most difficult de-soldering we’ve ever done. The board is much thicker and with large ground planes distributing all heat out of the de-soldered parts. I’m really surprised that the board survived the surgery.

We have even been able to setup the firmware properly to load Windows 2000. It looks like the unit was used only for demo purposes in Czech SGI so nothing interesting is installed on the hard drive.

SGI Visual Workstation 320 restoration #1

  • by

SGI 320 is an interesting piece of history – a failed attempt of UNIX workstation manufacturers to dominate the professional PC/Windows market. Czech SGI guys gave me this computer for free a year ago when they moved to a new office building.

Unlike standard computers of the era running Windows, this one is not PC compatible. It supports only Windows NT 4.0 and 2000 and only via a special loader. You cannot run DOS on it. The logic board badly needs to replace all capacitors (some of them are already leaking) and one voltage regulator which tried to desolder itself from its position. On the other side, it still POST without any issue and passes all tests.

Now I have to wait a few weeks for all the ordered parts. This oddity deserves to survive. I’m really curious about the performance achieved by the unified memory architecture when working with analog (AV in) and digital (firewire) video signals and OpenGL.

The OpenGL performance shouldn’t be bad. John Carmack used the SGI 320 workstation when working on Quake 3 Arena…

Higher Refresh Rate in DOS Games

  • by

I decided to stay in my parent’s house for a weekend and although almost all my computer equipment is somewhere else for a long time, under a thick layer of dust I’ve found my old Compaq DeskPro SFF box and a 17-inch CRT that my father bought new in 1998. Surprisingly, the system still works and its hard drive is loaded with many DOS and early 3D-accelerated games… Great time to play all episodes of Blood (a game based on the Duke Nukem 3D engine).

I like playing old games on CRTs but I hate low refresh rates used in DOS games (60-70Hz). If you have as sensitive eyes as I have, there is a solution called UniRefresh. It can modify default refresh rates for each supported resolution and it works well with most games that use VESA. That allowed me to play the game in 640×400@120Hz. Yay!

UniRefresh needs a graphics card supporting VBE 3.0 (VESA BIOS Extensions). Use the latest DOS version of SciTech Display Doctor to emulate VBE 3.0 support on older cards.

Excel 2.0 (1987)

  • by

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)

  • by

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.

HP 9000/C100 Graphics Workstation (1995)

  • by

My C100 is not as nice as the one on Wikipedia, but it’s fully working. The machine was used in a small GIS company as a server for two X terminals (probably HP 700X). It is equipped with 100-MHz PA-7200 CPU, 256 MB of RAM, 2-GB SCSI HDD, two additional 100-Mbit/s network NICs and a single-head version of the HP 8-bit frame-buffer card. The original owners used it with an external SCSI drive for user data and did regular backups using the internal tape drive. They didn’t delete anything from the internal system drive when they stopped using it (the drive has only about 10 megs of free space).

Owners were probably smokers so I had to clean the internals of the machine from the greasy dust. Fortunately, there was no visible corrosion on logic boards. Now it is ready for a fresh installation of the HP-UX operating system including the complete aC++ development environment.