mlinar@eve.usc.edu (Mitch Mlinar) (11/26/90)
In article <1990Nov22.110949.12852@hayes.ims.alaska.edu> floyd@hayes.ims.alaska.edu (Floyd Davidson) writes: >In article <1990Nov22.030504.6649@simasd.uucp> donm@pnet07.cts.com (Don Maslin) writes: >> In order to use QD drives you need to make changes to both ROM and >> BIOS. There are/were a couple of outfits that had slightly >> differing versions: Advent's TurboROM and Micro Cornucopia's MAX >> ROM. > >I installed a TurboROM on a K-10, and once had a copy of the first >ROM that Micro C sold. I don't recall that the BIOS needed to be >changed with either of them. Mind you I could be wrong on that, >but if I remember right all the code that handles disk blocking and >so on is in the ROM, all the BIOS does is call the ROM. On most >earlier CP/M systems that code was actually in the BIOS itself. Floyd is part right: all blocking/deblocking of of disk sectors is done in the ROM itself. And, although you can use the original BIOS with two of them (not KayPLUS - the third), why would you want to? The original Kaypro BIOS is pretty poor and makes some bad assumptions. See below. As far as ROMs, actually MicroCornucopia ROMS are pretty poor, but they were the *first* Kaypro replacement. Both TurboROM and KayPLUS are much more powerful and flexible. There is also no need to screw around with assembly language in KayPLUS (and I think TurboROM, too), just run a configuration program. Regarding BIOS: Kaypro assumed that you were in an 8080 world AND interrupts do not exist. (They wrote their BIOS in Z80 code, though, and used the "back-side" Z80 registers.) Bridger Mitchell (TurboROM) is better here in that he understands that interrupts might exist, but ALSO assumes that one lives in an 8080 world only. In other words, the assumption is that IX and IY registers are unchanged outside of your program. KayPLUS does not make any of those assumptions, especially since 90% of the CP/M computers are Z80 and replacement operating systems (like QP/M or ZCPR) all exploit the Z80 instruction set. The most fun I have had in writing code has been the lack of understanding about interrupts. I like to use them because they improve throughput. Even early DBASE and Wordstar code fails on interrupt driven CP/M architectures. Most code I have seen in CP/M in recent years has finally gotten much better in its understanding of the processor and interrupts. KayPLUS (MICROCode Consulting) is still sold by Emerald Microware. -Mitch
floyd@hayes.ims.alaska.edu (Floyd Davidson) (11/26/90)
In article <28387@usc> mlinar@eve.usc.edu (Mitch Mlinar) writes: >In article <1990Nov22.110949.12852@hayes.ims.alaska.edu> floyd@hayes.ims.alaska.edu (Floyd Davidson) writes: >>In article <1990Nov22.030504.6649@simasd.uucp> donm@pnet07.cts.com (Don Maslin) writes: >>> In order to use QD drives you need to make changes to both ROM and >>> BIOS. There are/were a couple of outfits that had slightly >>> differing versions: Advent's TurboROM and Micro Cornucopia's MAX >>> ROM. >> >>I installed a TurboROM on a K-10, and once had a copy of the first >>ROM that Micro C sold. I don't recall that the BIOS needed to be >>changed with either of them. Mind you I could be wrong on that, >>but if I remember right all the code that handles disk blocking and >>so on is in the ROM, all the BIOS does is call the ROM. On most >>earlier CP/M systems that code was actually in the BIOS itself. > >Floyd is part right: all blocking/deblocking of of disk sectors is done >in the ROM itself. And, although you can use the original BIOS with two >of them (not KayPLUS - the third), why would you want to? The original >Kaypro BIOS is pretty poor and makes some bad assumptions. See below. Hey, what I said was that to use QD disks you don't *have* to change the BIOS. Thats is totally true, (I think). As to why would one want to use the original BIOS: only if you can't get or program a new one. I'll go along on that. Floyd -- Floyd L. Davidson floyd@hayes.ims.alaska.edu Salcha, AK 99714 paycheck connection to Alascom, Inc. When I speak for them, one of us will be *out* of business in a hurry.