5 ms·
What I find interesting is things like the Atari Portfolio and HP 200LX could run their versions of DOS for quite a while on a couple AA batteries.
by mysterydip 3y ago
What I find interesting is things like the Atari Portfolio and HP 200LX could run their versions of DOS for quite a while on a couple AA batteries.
- bombcar 3y agoIIRC they had some basic "suspend to RAM" where when they closed they just barely kept the RAM alive and didn't power anything else.
- p_l 3y agoWhile Atari Portfolio used the CMOS version of 8088, I believe HP ones made the jump to 80186 (or compatibles) which AFAIK had, among other things, dynamic frequency setting
- bombcar 3y agoCorrect - the x00LX (I think the 95 also) were one of the few mass produced computers to use the rare 186.
- bitwize 3y agoThe HP 200LX and similar used a 186-compatible CPU called "Hornet". Using an actual 80186 in a PC compatible would have been damn near impossible; the 186 was a system-on-chip design that had built-in timers, an interrupt controller, and other gubbins. Some of these were mapped to devices that had other devices mapped to them in the PC design, so building a 186-based system that met the common threshold for PC compatibility (i.e. it ran the IBM versions of Lotus and Flight Simulator acceptably well) was a nearly insurmountable task. Because it acted more like a real OS, with user programs calling through driver APIs rather than touching the hardware directly, with the right driver support Windows could run on a 186-based system; one (the Tandy 2000) was used to develop Windows 1.0's color modes because it had a high-resolution 8-color display before the EGA came out: https://www.1000bit.it/lista/t/tandy/tandy2000_ad.jpg https://www.1000bit.it/lista/t/tandy/tandy2000_ad.jpg ISA-compatible "clones" of the 186, like the NEC V40 and the "Hornet", did not have the SoC problem and could be used in PC-compatible system designs.
- userbinator 3y agoIn other words, it has a 186-class ISA but isn't the actual 186 SoC.
- pdw 3y agoIt was never really clear to me if the "Hornet" was a custom design Intel did for HP or if "Hornet" was just the codename for the 80C186EA, a 186 with added powersaving support. Either way those palmtops were quite cool machines.
- rep_lodsb 3y agoFor what it's worth, I've used a HP 200LX to confirm that some undocumented details (found by disassembling microcode) work as expected: REP BOUND only compares against lower bound REP MUL result in AH (byte) or SP (word) REP IMUL result in CH (byte) or BP (word) REP IMUL reg,r/m,i16 first operand ignored, 32 bit result in DX:AX REP IMUL reg,r/m,i8 first op ign., AH=result bit 23..16, AL=bit 7..0 AAM 00H no "divide by zero" exception, AH=FFh, AL unchanged So it's certainly based on the 80186 microcode, as none of these instructions do the same on any other x86 chip.
- bombcar 3y agoThis is perhaps the comment that most aligns with a username I’ve ever seen ;)
- lproven 3y agoThanks for the best explanation of the '186 I've seen in 30 years. :-)
- bitwize 3y agoNo problem! The more you know, right? I mained a used Tandy 2000 for a while as a kid/teenager. Back when it came out, computers still came with full technical docs, including Intel's extensive 186 documentation. I've forgotten things about that beleaguered chip many enthusiasts never knew.
- ralferoo 3y agoResearch Machines made a sizable inroad into UK schools with their range of computers from the late 1970s to early 1990s. One such example is the RM Nimbus: https://www.computinghistory.org.uk/det/41537/RM-Nimbus-PC-(Later-Beige-Model)/ https://www.computinghistory.org.uk/det/41537/RM-Nimbus-PC-(... It had a 186 from the very first models, and was later re-branded as PC-186 when they introduced their 286 model.
- lproven 3y agoIndeed so. The BBC Micro Master 512 was the only other one I saw.