Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!wuarchive!zaphod.mps.ohio-state.edu!mips!pacbell.com!pacbell!ditka!qiclab!techbook!fzsitvay From: fzsitvay@techbook.com (Frank Zsitvay) Newsgroups: comp.os.cpm Subject: Re: CPM Companion Message-ID: <1990Sep26.091021.14560@techbook.com> Date: 26 Sep 90 09:10:21 GMT References: <9009191229.aa09295@crdec8.apgea.army.mil> Organization: TECHbooks of Beaverton Oregon - Public Access Unix Lines: 81 In article <9009191229.aa09295@crdec8.apgea.army.mil> mdgoodma@CRDEC8.APGEA.ARMY.MIL (Mack Goodman) writes: >Could someone send me a brief description of what this device >is, and could it be useful for me. I have a Northstar Advantage. >This device is called " CPM Companion 2.2 " It is a black box >with a couple of ports on it and a "edge" connector? > >Private replys may be most appropriate, Thanks in advance. > >Mack Goodman i apologize for this seemingly unseemless thread, but the local piece of s--t mail system here keeps barfing this mail message back to me, which really doesn't make a whole lot of sense since we had this thread going in mail for the past 2 or three cycles. (i know it's a local thing because the system barfs the message within 10 seconds of sending it.) now, back to the discussion.... when this thread was so rudely interrupt by a flakey mail system, Mack Goodman wanted to know how to get his Companion (a cp/m 2,2 machine) up and running, mainly because his northstar advantage didn't know what to do with a soft sectored disk. --- well, the companion would be able to read and write soft sectored disks with no problem, assuming you could find a boot disk for it. if you can find such a disk, then you would be home free. just gut the ns advantage and use it's disk drives for the companion, and term software on the ns itself. whether a system uses hard sector or soft sectored disks is mostly a function of the controller. check the controller in the advantage and see if it uses a 179x or a 765 chip. if it does, then it's a matter of software. if it uses discrete logic, or one of the 177x controller, then you're out of luck. i say 179x and 177x meaning the series, as there is a 1791 and a 1793. same for the 177x series. the differences is in the interface electronics, but both are the same from a software point of view. if you are knowledgable about cp/m and assembly language, you can do one of two things... either configure cp/m for the companion, or rewrite the bios routines in the advantage to allow the use of soft sectored disks. and, if you can find a bios listing for a kaypro or other good cp/m machine, you could hack that until it works. this is basically how products like uniform work, they replace those sections of the bios with code similar to the machine it's trying to emulate the disk format. for the advantage, if it uses a 179x controller chip (like most decent cp/m machines do) then all you would need are the addresses of the controller ports. get a bios listing for sometthing like a kaypro, and just change the addresses in the bios to point to the right place. do this in ram with ddt and sysgen it onto a disk, and you would have yourself a boot disk for any floppy you want. for the companion, you would do something similar, except you would have to find the ports addresses, and since you don't have any docs, that can be somewhat difficult. what i would do is open the machine, and look at the circuit board traces to see what address the controller chip is located, and go from there. once you get a disk system working on the companion, the rest is easy, since then you could do your system exploring via software on the machine itself, which is much easier in my opinion from doing it from circuit board traces. where are you located at?? you might be able to find a cp/m machine cheap, and you wouldn't even need to do some serious hacking to get it working, either. unless it is something you like do, which is why i go through this sort of torture. (one man's pleasure, another man's pain...) i don't suppose a month goes by where someone offers their cp/m machine to me for the price of hauling it away. if you look, you can find some real bargains out there... -- fzsitvay@techbook.COM - one of these days i'll get it right... Version 2 of anything is usually the version that works.