test-drb April 2005

test-drb@ccmp.vtda.org

269 participants
730 discussions

by andyda＠mac.com

First, Thanks for all the helpful suggestions! I plan to swap the RAM around this weekend, and do as Tony suggested, which is to use my VOM just to see if the clocks and/or address data lines are stuck high or low. I also have the assembler and basic ROMs installed (they were both options when my AIM was new) and I guess maybe it might be a good idea to remove them as well, just to have only the absolute minimum on the board. Also, I have been corresponding with another person off-list, so maybe I can get this thing repaired after-all!! :) Couple of things about general AIM-lore: Most AIM 65's were sold as boards, the case came later, but I never got around to getting one. 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. The stock AIM 65 did not come with the Assembler or Basic (those were options) Later Rockwell also offered a set of FORTH ROMs ( I have them, never did program much FORTH though) The stock AIM 65 was offered with either 1K or 4K RAM, I bought a 1K and a guy I knew at Rockwell gave me the other 3K. Way back then, I used to be a consultant, did most of my work with Rockwell PPS 4 and PPS 8 and 6502 I even used to teach seminars for Rockwell to their customers on PPS 4 and 8 (mostly PPS 4). The AIM 65 was a fair development platform, we used to use a Rockwell System 65 for much of our code development and test, but we also used the AIM 65 for development and test, and I could also my AIM 65 at home when I didn't go to the office. Way more than anyone wanted to hear, I hope it is not too long a message. Later, AndyD

19 years, 8 months

cctech Digest, Vol 20, Issue 31

by james＠attfield.co.uk

If you hit T from an RDOS prompt it will enable the upper 32K, copy itself to 0xC000 and re-issue the prompt. I'm not quite sure where the stack goes, perhaps K still works to kick the stack. Not sure if this also works on a 4FDC Jim Message: 12 > Date: Sat, 16 Apr 2005 00:04:20 -0500 > From: "Randy McLaughlin" <cctalk at randy482.com> > Subject: Re: Some said they have CDOS and Cromemco disks > To: "General Discussion: On-Topic and Off-Topic Posts" > <cctalk at classiccmp.org> > Message-ID: <003b01c54241$c76faf60$023dd7d1 at randylaptop> > Content-Type: text/plain; format=flowed; charset="iso-8859-1"; > reply-type=original > That's great! I can make a few suggestions: > > I can send you older CDOS's that should be more memory lean. Some older > CDOS's had normal SA800 support via undocumented drive type 'X' > even though > CDOSGEN only references 'S'mall & 'L'arge. > > If you have 64K of RAM RDOS can be copied to RAM giving you access to the > full 64K allowing Larger CDOS's: Using a random address such as 1000H: > > ld hl,0C000H > ld de,2000H > ld bc,1000H > ldir > ld a,1 > out (40H),a > ld hl,2000H > ld de,0C000H > ld bc,1000H > ldir > ret > > Just use the substitute memory command to enter the above code > (hex) and do > a g 1000 (a return returns to RDOS). You are now running RDOS out of RAM. > You can have one 32K CDOS and maybe a 64K CDOS to transfer. BTW you never > have to use 8080 only opcodes since RDOS & CDOS only run on > Z80's. Also the > above code can go in any free space and is not address dependent. > > > Remind people of my favorite mantra: 3.5" drives with DD media will be > happy to act as 5.25" DD drives. > > > Randy

19 years, 8 months

Searching: Info about Racal-Redac Monarch

by gerold.pauler＠gmx.net

Part of my last haul of pdp8/e equipment (more about this will follow when pictures are online) are 20 to 30 8" floppies labeled "Racal-Redac Monarch System Disks", etc. A quick google showed nothing relevant. Any info about this would be appreciated. Thanks Gerold

19 years, 8 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: Ben Franchuk <bfranchuk at jetnet.ab.ca> >> The Zilog SIO types are fine by me. The yard sale full of assorted >> and scattered registers is annoying, but programmers opinions >> don't count. It does pretty much everything required for >> full-featured async. At least it does what you tell it to. They seem to. Darn things were never cheap though but being two for one made them tolerable if you needed two. >Well I favor dumb chips at the moment because I don't have >several MEG or EPROM to bootstrap my HOMEBREW computer.Infact I have >no PROM of any kind, just toogle switches*. Since I favor a 6809 >style of memory access** I am using 68B50's. I just need to finish >the CPU logic design and build it. :) I kinda liked that one to. The MITS 2SIO card used them and it worked very well. That was for 8080, works well for 8085 too. Allison

19 years, 8 months

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

by ajp166＠bellatlantic.net

> >Subject: Re: 7201 (was Re: Z8530 (was Re: Navtel 9460 Protocol Analyzer info?)) > From: Scott Stevens <chenmel at earthlink.net> >You might want to check out the 6402. I have a bunch of them from some >syncronous modems I scrapped a few decades back. It has the distinction >of being from the same family as the 6100 'PDP-8 on a chip' micro, and >is fairly bare-bones. It has several simple registers, but much of the >config is done with hardware by enabling pins and what-not. ;) I have a few. They go well with 6100, 6120 and 1802 being cmos. Allison

19 years, 8 months

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

by ajp166＠bellatlantic.net

>Subject: Re: 7201 (was Re: Z8530 (was Re: Navtel 9460 Protocol Analyzer info?)) > From: "Eric Smith" <eric at brouhaha.com> >I've been saying for years that hardware design is far too important >to be left up to hardware engineers. :-) At an interview once They asked me what kind of engineer I am? I kept it fairly simple. I design things, I fix things and sometimes I fix things others designed. Hardware and software sould never be designed in isolation, they become poor partners from their estrangement. It's a good thing have all elements on friendly terms. Then again, lifes tough enough but, then we have commercally available parts. ;) Allison

19 years, 8 months

Dead AIM ^%??

by andyda＠mac.com

Well, I tried the next steps, with my limited equipment, and no joy. Here's what I've tried so far, 1. visually inspect - looks OK, nothing obvious like cracked or discolored components 2. check power supply - OK 3. check voltages on board - OK 4. remove extra ROMs 5. check clock with analog VOM - did not appear stuck high or low 6. check low addess lines with analog VOM - did not appear stuck high or low 7. remove all but low order RAM 8. swap RAM to try to find if bad zero page RAM - could all 8 RAM be bad? 9. feel parts for heat - nothing extraordinary, all appeared cool to touch I have an offer of someone (he's got 6 AIMs) I can mail it to, and he said he would look at it, but if there is something I can do here I would not have to impose on him. Any more ideas, or have I reached the end of what I can do here? BTW: I am not comfortable with de-soldering and soldering, it's just been too many years. I'm out of practice. So let me know anything you think I can try (W/O solder) and I'll try. Thanks again for such a wonderful response. Later, AndyD

19 years, 8 months

N8234N datasheet

by rigdonj＠cfl.rr.com

Does anyone have a datasheet for these? I THINK they're Quad 2 input multiplexers but I'm not sure. I found them in an i8008 computer system. Joe

19 years, 8 months

N8234N datasheet

by rigdonj＠cfl.rr.com

Oops! I meant to add that these are 16 pin DIP packages and appear to have been made by Signetics in the early 1980s. Does anyone have a datasheet for these? I THINK they're Quad 2 input multiplexers but I'm not sure. I found them in an i8008 computer system. Joe

19 years, 8 months

Some said they have CDOS and Cromemco disks

by dave04a＠dunfield.com

Hi Randy, >I can send you older CDOS's that should be more memory lean. Some older >CDOS's had normal SA800 support via undocumented drive type 'X' even though >CDOSGEN only references 'S'mall & 'L'arge. That would be ideal - It would be nice if I could skip the intermediate step of making a SSSD and go straight to making the final disks. It would also eliminate the requirement to have 48k in order to transfer the final disks. I'll email you the transfer program - perhaps you can read in a version of CDOS that INITs in 32k and send it back to me. Btw, it's pretty easy to test: - Gen a CDOS for 32k - Boot it, run INIT but don't respond to the first prompt - Reset system - Enter G100 - INIT will startup again, try formatting DSDD disk and see if it works. When I try to do a DSDD disk under 32k CDOS I get: Logical disk error 03h, drive 'h', block BC7241h Under a 48k or 64k CDOS it works fine. >If you have 64K of RAM RDOS can be copied to RAM giving you access to the >full 64K allowing Larger CDOS's: Using a random address such as 1000H: > >ld hl,0C000H >ld de,2000H >ld bc,1000H >ldir >ld a,1 >out (40H),a >ld hl,2000H >ld de,0C000H >ld bc,1000H >ldir >ret > >Just use the substitute memory command to enter the above code (hex) and do >a g 1000 (a return returns to RDOS). You are now running RDOS out of RAM. >You can have one 32K CDOS and maybe a 64K CDOS to transfer. BTW you never >have to use 8080 only opcodes since RDOS & CDOS only run on Z80's. Also the >above code can go in any free space and is not address dependent. I thought about doing this - in fact, you can use the 'T' command to cause RDOS to copyitself to RAM ... but I would like to keep it running in 32k as this is more easily achieved configuration in many cases. I've put together a bit of documentation, and I have the transfer program as well as CDOS and Cromix images ready to put up, however I'm having a bit of trouble with permissions on the server (which is remote to me)... I hope I can get it resolved this weekend and get the files up. Regards, Dave -- dave04a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.parse.com/~ddunfield/museum/index.html

19 years, 8 months

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test-drb April 2005