test-drb April 2005

test-drb@ccmp.vtda.org

269 participants
730 discussions

by pat＠computer-refuge.org

The seller (obviously) doesn't know much about it, but it appears to be a fairly large deskside IBM machine from around 1980. Link to auction: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5185251356 Ideas, anyone? Pat -- Purdue University ITAP/RCS --- http://www.itap.purdue.edu/rcs/ The Computer Refuge --- http://computer-refuge.org

19 years, 5 months

7201 (was Re: Z8530 (was Re: Navtel 9460 ProtocolAnalyzerinfo?))

by ajp166＠bellatlantic.net

> >Subject: Re: 7201 (was Re: Z8530 (was Re: Navtel 9460 ProtocolAnalyzerinfo?)) > From: woodelf <bfranchuk at jetnet.ab.ca> >Has anybody made a easy to use serial chip, all seem to be lacking some >feature? >The only way I like to program is I/O is 'hardware" setup ... Dip >switches and hard reset >lines. :) What you want then is a MITS SIO-B. Has a COM2502. That generation of chips trade extreme simplicity for dip switches and loads of support chips. When I build and use serial I look at a few things: Chip count < the fewer I have to wirewrap the better> Functions I want <Vs gobs of unused features> Availability (are they in my stock) Usually I end up with 8253 countertimer as BRG and 8251, or 8250. Though the 6850 is friendly enough. I also have others to pick >from like 6850, 7201, Z80SIO, 2681 and others. Allison

19 years, 5 months

Dead AIM 65??

by andyda＠earthlink.net

> Couple of things about general AIM-lore: > > The original AIM 65 (not the AIM 65/40) had a 20 char alpha LED > display. The Aim 65/40 had a 40 character vacuum fluorescent display > and 40 character printer, much more friendly for development than the > 20 char display and printer. : I think I have heard of the AIM 65/40... if someone here knows such : things, was the motherboard re-engineered? Is it possible to retrofit : the 40-col display to the original AIM? Also, was the 40-col VFD run : by something like an HD44780 chipset, or was it some kind of raw : interface? These days, 40x1 or 40x2 VFDs based on the HD44780 are not : difficult to locate and are not all that expensive. They are also :trivial to send chars to. : -ethan The AIM 65/40 was quite different from the original AIM 65, it was really useable as a fairly powerful, though inexpensive 6502 development system. I never used one as I left consulting in 1980, but I did see one, and it appeared to be a pretty good computer. More details can be found at: http://oldcomputers.net/AIM-65-40.html which has info on the AIM 65/40 (which came in several models) and a Rockwell Design Center (which I never used) and System 65, which I did use and thought it was a very capable development system. As you can see, the AIM65/40 is a completely new board, I don't know if one could use the 40 Char display on a normal AIM 65, but I suppose you could, you would just need to write new driver software for it, maybe replace the AIM 65 ROMS with EPROMS with most of the AIM 65 OS and new drivers for the display. Could be an interesting Project, but it could compromise an otherwise vintage computer (the AIM 65) in the process. IHTH, AndyD

19 years, 5 months

7201 (was Re: Z8530 (was Re: Navtel 9460 Protocol Analyzerinfo?))

by ajp166＠bellatlantic.net

>Subject: Re: 7201 (was Re: Z8530 (was Re: Navtel 9460 Protocol Analyzerinfo?)) > From: Ethan Dicks <ethan.dicks at gmail.com> >I have *hundreds* of COM5025 chips on the shelf here. Never found a >use for them. Use them to make FDC for PCs to do other formats. ;) Allison

19 years, 5 months

Some said they have CDOS and Cromemco disks

by ajp166＠bellatlantic.net

> >Subject: Re: Some said they have CDOS and Cromemco disks > From: "Randy McLaughlin" <cctalk at randy482.com> >The only real issues are either differences in different soft-sectored >controllers (Western Digital based chips have some formats that the 765 >based chips can't handle but are rarely used) or the basic ability to handle >FM (as in 3740 format). The difference between 1771 and 765 are that 765 only does IBM style formats FM or MFM. As a result you only supply Cylinder, Head, Record<sector>, and N a lenth encoding. The 1771 you pump every byte required for the entier track until it times out. That difference is significant as one was designed as a IBM format controller and the other was more universal. However the 765 series chip does do FM and at all data rates. Many boards for PCs limit that by not implmenting needed peices or not supporting it in the bios. So if the 765 based controller doesnt do any of the common formats (especially FM) blame the designer of the board. Allison

19 years, 5 months

7201 (was Re: Z8530 (was Re: Navtel 9460 Protocol Analyzer info?))

by ajp166＠bellatlantic.net

>Subject: 7201 (was Re: Z8530 (was Re: Navtel 9460 Protocol Analyzer info?)) > From: "Eric Smith" <eric at brouhaha.com> >That chip sucked when used as a plain old UART. In order to handle slight >speed mismatches between two modems emplying synchronous modulation, ;-) It was nearly a full clone of the Z80 SIO with one difference, the interrupt logic matched the 8085/8086 rather than Z80. As a simple SIO it was a major pita to use, too dang many registers. As a result I ahve a bunch of them and never use them. Ise the 2681, 8251 or 8250 before that beastie. The only thing worse to design with and use was the COM2501, dumb as a stump. Allison

19 years, 5 months

OT: Prank paper accepted for computer comference

by r_a_feldman＠hotmail.com

This is OT, but computer related. A computer-generated nonsense paper was accepted for presentation at the World Multiconference on Systemics, Cybernetics and Informatics (WMSCI). The story is at: http://news.bbc.co.uk/2/hi/americas/4449651.stm and the paper can be read at: http://www.pdos.lcs.mit.edu/scigen/rooter.pdf Bob

19 years, 5 months

OS Challenger Video?

by Watzman＠neo.rr.com

Re: "Can the Challenger drive a compostite video monitor directly or is it only designed to drive an RF modulator?" Since the input to a modulator is a composite video signal, the answer is that both of your "or" options are the same thing. However, some of the OSI video cards were 5-signal outputs (red, blue, green, H sync, V sync) which, in terms of your question, would be "neither". It's not difficult, however, to mix the two sync signals with one of the video signals and then drive a monochrome monitor or a modulator.

19 years, 5 months

CP/M-80 Kermit source, in TDL/Xitan Z80 mnemonics, anyone?

by tomj＠wps.com

I know this is a long shot, but does anyone have a Kermit assembler source for the Phoenix Software Associates PASM assembler? I'm lazy, and trying to avoid lots of tedious editing to convert from some other version. Or a BDS C version?

19 years, 5 months

Some said they have CDOS and Cromemco disks

by Watzman＠neo.rr.com

I put a bios and boot code up on Howard Harte's site some time ago. This was source code for CP/M 2.2 (and it's in 8080 MAC/ASM assembler). If you have a working system, it's not too difficult to get this running. Again, the source code can be downloaded from Howard's site. As it exists, it's configured for 8". Should not be difficult to modify for 5.25". It works, I'm actually running it on a 16FDC (I believe that it will work on a 4FDC also).

19 years, 5 months

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test-drb April 2005