4 ms·

I had a similar machine when I was in highschool - a Texas Instruments Professional Computer. It had the same basic form factor and build quality as an IBM 515

by 13of40 4y ago

I had a similar machine when I was in highschool - a Texas Instruments Professional Computer. It had the same basic form factor and build quality as an IBM 5150 PC, an ISA bus, and MSDOS 1 and 2 (so int 21 worked), but the BIOS was incompatible. That was always a bit of a head scratcher to me, since even if the hardware ports and video memory were laid out differently, you could still make the BIOS interrupts compatible.

thought_alarm 4y ago
The TI-PC was released around the same time that Compaq was ushering in the era of the 100%-compatible PC clone. Compaq, of course, created the first 100% compatible clean-room implementation of the BIOS, modified MS-DOS to work with it, ran an extensive compatibility lab to ensure existing PC software worked correctly with their BIOS/MS-DOS combo, and gave their changes back to Mircosoft to encourage the growth of a standardized platform. Unsurprisingly, Compaq was founded by ex-TI engineers who became disillusioned with the TI's management.
- UncleSlacky 4y ago
  I recall TI Professional PCs were repurposed as terminals in the TI factory in Bedford (UK) as late as 1991, and I'd guess other TI sites were also using them for the same purpose at that time.
djur 4y ago
I was curious about why it would have been PC incompatible, so I did some searching. Didn't find any answers, but Wikipedia led me to this incredibly detailed contemporary review in Byte magazine: https://archive.org/details/byte-magazine-1983-12/page/n287/mode/2up https://archive.org/details/byte-magazine-1983-12/page/n287/... I enjoyed reading it. At one point the reviewer dials in to The Source (an early competitor to CompuServe) to download a BASIC program. The ads are great, too.
- 13of40 4y ago
  If I could have had that interrupt list and memory map (tables 1 & 2) when I was 16, that would have been a game changer. As it was, the machine was already obsolete when we thrift-stored it, so there was no way to get software or manuals besides what came with it. I still did a fair amount of BASIC and DOS-level assembly programming on it, but the hardware and BIOS was a black box.
analog31 4y ago
Likewise, I had a Sanyo MBC550 computer, which came with its own MS-DOS, but would not run some (most) IBM PC software. Software that bypassed the "official" API, typically for the sake of speed gains, easily became tied down to the IBM PC memory map. Thankfully, there were separate versions of some apps that ran on generic MS-DOS, including the original Turbo Pascal, and Word Perfect, so the computer got me all the way through college. Why did I choose the Sanyo, you ask? I was able to get a complete computing system, with display, printer, and "bundled" software, for under US $1000.
- smackeyacky 4y ago
  I had one of these growing up too - for largely the same reason (2nd hand it was much cheaper than an IBM clone). We ran Wordstar on it, which worked AFAIK out of the box with no modifications. Everything else was a crap shoot. The screen was incredibly slow too, like using a terminal over a slow modem. It got me through university though.

by 13of40 4y ago

thought_alarm 4y ago

The TI-PC was released around the same time that Compaq was ushering in the era of the 100%-compatible PC clone. Compaq, of course, created the first 100% compatible clean-room implementation of the BIOS, modified MS-DOS to work with it, ran an extensive compatibility lab to ensure existing PC software worked correctly with their BIOS/MS-DOS combo, and gave their changes back to Mircosoft to encourage the growth of a standardized platform. Unsurprisingly, Compaq was founded by ex-TI engineers who became disillusioned with the TI's management.

UncleSlacky 4y ago
I recall TI Professional PCs were repurposed as terminals in the TI factory in Bedford (UK) as late as 1991, and I'd guess other TI sites were also using them for the same purpose at that time.

djur 4y ago

I was curious about why it would have been PC incompatible, so I did some searching. Didn't find any answers, but Wikipedia led me to this incredibly detailed contemporary review in Byte magazine: https://archive.org/details/byte-magazine-1983-12/page/n287/mode/2up https://archive.org/details/byte-magazine-1983-12/page/n287/... I enjoyed reading it. At one point the reviewer dials in to The Source (an early competitor to CompuServe) to download a BASIC program. The ads are great, too.

13of40 4y ago
If I could have had that interrupt list and memory map (tables 1 & 2) when I was 16, that would have been a game changer. As it was, the machine was already obsolete when we thrift-stored it, so there was no way to get software or manuals besides what came with it. I still did a fair amount of BASIC and DOS-level assembly programming on it, but the hardware and BIOS was a black box.

analog31 4y ago

Likewise, I had a Sanyo MBC550 computer, which came with its own MS-DOS, but would not run some (most) IBM PC software. Software that bypassed the "official" API, typically for the sake of speed gains, easily became tied down to the IBM PC memory map. Thankfully, there were separate versions of some apps that ran on generic MS-DOS, including the original Turbo Pascal, and Word Perfect, so the computer got me all the way through college. Why did I choose the Sanyo, you ask? I was able to get a complete computing system, with display, printer, and "bundled" software, for under US $1000.

smackeyacky 4y ago
I had one of these growing up too - for largely the same reason (2nd hand it was much cheaper than an IBM clone). We ran Wordstar on it, which worked AFAIK out of the box with no modifications. Everything else was a crap shoot. The screen was incredibly slow too, like using a terminal over a slow modem. It got me through university though.