bill@bilver.UUCP (Bill Vermillion) (07/04/89)
In article <17323@gryphon.COM> gmadison@pnet02.cts.com (George Madison) writes: >wilso_d@cs.odu.edu (DeWitte Wilson) writes: >>Actually, I'm wondering even why they still sell the Model IV's. I > >I believe it has something to do with some contracts Tandy has with some >school districts about computers. I agree the price is WAY out of line. > >I don't know if you'd be interested in this, but several people on GEnie are >talking about the possibility of designing a new, Model-4 compatible >motherboard around the Z-280 processor. The idea is that you'd drop this >board into an inexpensive PeeCee case, add a similarly inexpensive PeeCee >power supply and monochrome monitor, and VOILA! They're thinking about such >things as an enhanced floppy controller that would deal with the new breed of >1.44MB floppies, built in hi-res graphics, lots of RAM on board, SCSI support, >and so on. If they do what a manufacturer of a new Z-280 based CP/M machine >are doing and include an IBM-PC buss, we could use "their" HD controllers, >etc. directly. (Remember, the Z-280 has a 16MB address space!) > Hm - sounds good. But it has already been done. (Well almost already been done). There once was an add on hard drive supplier in California called Lobo drives. They built and expansion interface for the Radio Shack model I also. The only problem was that it would only run on VTOS (Virtual Technology Operating System). Randy Cook wrote that. He also wrote the 2.x series of OS for R/S. Because of problems LOBO bought the rights to VTOS and called is LDOS (Lobo DISK operating system). In a few months the rights were (assigned/transfered/bought/who-knows) to a Wisconsin firm (whose original name escapes me now) and the company was called Logical Systems - and the LDOS now became Logical Disk Operating system. The first LDOS was released in 1980. I heard rumors that they were negotiating with Zenith at the time to put it on a line of Z80's from them. This was about 1 year before IBM announced their PC and who knows, if it had happened (Zenith with LDOS) it could have changed directions that computing took. Anyway - the E/I for the Model I was released about the time RS dropped the Model I for the Model III, a redesign necessitated by stricter FCC requirements. The LOBO E/I was a wonder. It had 2 serial ports and could control up to TWELVE 14" HARD DRIVES at one time. (Or 5" drives, or 8" drives"). Well - to make a short story longer, Lobo decided to incorporate all their model I know how into a computer. It was called the Max80. It was Model I hardware look-alike. The real problem arose when the OS was delivered by Logical Systems. The OS was the Model III version adapted for model I hardware - and that caused all sorts of problems, and locked the Max into LDOS, or CPM2.2 or CPM3. The Max used a 5 Mhz Z80b, had 128k ram, a Z80 SIO that provided 2 serial ports which could be programmed up to about 500 kbs. A parallel port. A built in clock/calendar with trickle charge ni-cads, an expansion port, though similar to the model I was not 100% compatible (some timing problems if I remember correctly), a hard drive expansion bus that was close to the SASIs interface (now known as SCSI), and floppy drive connectors to support FOUR 5" drives AND FOUR 8" drives simultaneously. It also used the Hitachi video controller (so you could program your own character set if you wished). All of this cost $920 with both CPM and LDOS in 1981. And this was in a single unit keyboard. The extra ram could be bank switched in and I kept my system overlays in it as ram drive. There was a user designed add-in memory board and it could be made into a 512k unit, just as the Model 4's could. (A friend of mine had a 512k model 4 - and had the memory config'ed as a ram drive - FASTTTT!!!! Wow!) I personally think that one of the reasons for it's failure was that the staff at Lobo was primarily oriented on CPM lines and did not know LDOS. I was East coast support (har, de har har har) for LDOS from LOBO for awhile. I also was running the national support group. :1 One item you mentioned that was thought of was a new floppy controller. Well the Max used a Fujitsu controller int eh MB88xx series (exact number escapes me at the momemnt, not listed in this manual I am reading). Single Density 5" drives used 125kbs rate, DD 5" used 250kbs. However 8" DD used 500kbs and the Fujitisu had no problem since the Max was a 5Mhz machine. That transfer rate is consistant with the current HD 3.5 disks. I could probably hang one on the Max and tell it that was an 8" DD drive and go from their. Lot's of luck with the idea. (They'd probably be better off getting the Max rights and modifying it though). bill > > >|George Madison, a/k/a George The Bear Cub, a/k/a Furr ** BEAR POWER **| >|INET: gmadison@pnet02.cts.com 8-{)> ames!elroy!pnet02.cts.com!gmadison| >|GEnie: GEORGE.M Arctophiles & Barbophiles Unite! PLink: BEARDLOVER| > > "Wouldn't it be great if you could only get AIDS from giving money to > television preachers?" -- Elayne Boosler -- Bill Vermillion - UUCP: {uiucuxc,hoptoad,petsd}!peora!rtmvax!bilver!bill : bill@bilver.UUCP
gmadison@pnet02.cts.com (George Madison) (07/04/89)
Re: Modifying the MAX-80 I don't think so. In case you missed it, the design in question is a Model 4 compatible, based around the Z-*2*80 processor, which is to the Z80 as the 80286 is to the 8088! The Z-280 has a 16 MEGABYTE address space, on-chip MMU, and lots and lots of other goodies. The MAX design, good as it may have been, wouldn't be ANY help building a M4 compatible system around this CPU. A primary consideration for those working on this idea is that the existing M4 DOS (LS-DOS 6.3) be able to boot and run with no problems, assuring that the machine will be usable and useful until specialized software to take advantage of its special abilities is written. Sorry, it looks like this machine WON'T have a Model III mode. I don't know if they've settled on a clock speed yet or not, but Z-280's are available rated up to 25MHz! |George Madison, a/k/a George The Bear Cub, a/k/a Furr ** BEAR POWER **| |INET: gmadison@pnet02.cts.com 8-{)> ames!elroy!pnet02.cts.com!gmadison| |GEnie: GEORGE.M Arctophiles & Barbophiles Unite! PLink: BEARDLOVER| "Wouldn't it be great if you could only get AIDS from giving money to television preachers?" -- Elayne Boosler
uhclem@trsvax.UUCP (07/06/89)
<> R>(assigned/transfered/bought/who-knows) to a Wisconsin firm (whose original R>name escapes me now) and the company was called Logical Systems - and R>the LDOS now became Logical Disk Operating system. Try "Galatic Software". "Thank you, Uh Clem." Frank Durda IV @ <trsvax!uhclem> ...decvax!microsoft!trsvax!uhclem ...sys1!hal6000!trsvax!uhclem