test-drb December 2005

test-drb@ccmp.vtda.org

235 participants
580 discussions

trying to design my first micro- looking for "prior art" (6100and6809)

by compoobah＠valleyimplants.com

Sounds like I'm back with 6809 as being easier to work with. I'll sit down with what I've got here and see what I can come up with (I'm more interested in designing than just having a "soldering skills test"). Scott

18 years, 11 months

RL drive problems ...?

by henk.gooijen＠oce.com

Hi, I would like to hear from the specialists what they have to say about this problem. I finally got my 11/34C running again. It has an RL11 and has two RL02 and one RL01 connected. Most of the time I cannot boot RT11 from the RL02-DC, but sometimes the boot is successfull! If the boot fails, I see the READY lamp of the drive flash once, then the RUN light goes off, and the display shows 000004. BTW, at the end of the RL drive chain is of course the terminator. The cartridge was written while the system was still in my house (some 3 years gao, at some 20" Celcius), but the system is now in a 12" Celcius environment. Could the temperature difference make the disk too difficult to read in the nwe conditions? When RT11 runs, and I only do a .DIR command of the disk, is there something written to the disk? That could make the disk "useless", because of the 20"/12" Celsius issues? Another problem that I have since I have power for my systems is that the READY lamp of the RL01 is *always* ON. The FAULT lamp is OK - and is OFF. I have not yet investigated this problem, but hints in advance are appreciated :-) [would save me some time, to work on the other projects, like the floppy disk interface for the 6809 Core Board...] BTW, the system worked fine, 3 years ago ... it has power since a few weeks, and I had a lot of problem getting the 11/34C up and running, but that would be a different story too ... greetz, - Henk, PA8PDP This message and attachment(s) are intended solely for the use of the addressee and may contain information that is privileged, confidential or otherwise exempt from disclosure under applicable law. If you are not the intended recipient or agent thereof responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, please notify the sender immediately by telephone and with a "reply" message. Thank you for your cooperation.

18 years, 11 months

AMD bit-slice machines

by legalize＠xmission.com

Besides the Lilith Modula-2 workstation, what other computers were made from the AMD 29xx bit-slice architecture? -- "The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ: <http://www.xmission.com/~legalize/book/> Pilgrimage: Utah's annual demoparty <http://pilgrimage.scene.org>

18 years, 11 months

ZX80 - was: SN76477N

by dave04a＠dunfield.com

>Today I was looking for something (A Cipher 525 tape drive) that I bought >NOS years ago and left in its original box. I thought I'd found it, opened >the box and discovered a Sinclair ZX80 with the "A Course in BASIC >Programming" book. The problem is that I don't remember getting this >thing--I'm sure I didn't buy it. Maybe Dave McGlone tossed it in when we >were swapping junk years ago. (P.S. I did find the Cipher and discovered >that I bought two of them). > >I don't know if it works, since I don't know the polarity of the 9vdc >adapter. Either way, is this just common trash or is this actually worth >something?. My wife suggested that I throw it out; she figures that if I >didn't even know that I had it after all these years, that I certainly >don't need it now. The ZX80 is the immediate predecessor of the ZX81/Timex-1000, which are VERY common. The ZX80 isn't quite so common, but I think there should be lots around - although I've not stumbled on another one lately. I'm pretty sure the adapter is the same as the ZX81/T1000 - and if you take a look inside it's just a series linear regulator (7805) and it should be pretty easy to figure out the polarity - if you want, I can dig mine out and measure it. Don't toss it - Mines in sad shape (previous owner drilled holes to mount switches, broke the corner off the cabinet and lost the original integer ROM after upgrading to the FP rom) - I've been keeping a lookout for a better specimen, however as noted above I haven't run across one yet. I'd be happy to give it a better home than the dustbin. 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

18 years, 11 months

"Market" for old macs?

by trixter＠oldskool.org

At work I have an SE30, LC, IIci, and a 603 variety mac just... lying around. Are these things as common as dirt, or should I snag them? I ask because I'm reminded of the "x86 dead zone" -- a zone where a machine isn't old enough to be compatible with older software, but isn't new enough to be useful (a Pentium 133 falls into this category -- can't run old stuff, can't run new stuff, so toss it in the garbage). -- Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/ Want to help an ambitious games project? http://www.mobygames.com/ Or check out some trippy MindCandy at http://www.mindcandydvd.com/

18 years, 11 months

Where to buy a Selectric?

by shoppa_classiccmp＠trailing-edge.com

I'm looking to get a nice IBM Selectric typewriter - for typewriter, not computer console, use. Not too picky as to typeball etc., but if someone wants to tell me what to look for and what to avoid, I'm all ears. In the past I've used both Selectric II's and III's and can't say I prefer one over the other. I am looking to keep it for many years with only light to moderate use so reliability/parts availability is somewhat important. Anyone want to recommend a US (or Washington DC) area dealer who stands above the rest? Or should I just take my chances on E-pay? Is there a more appropriate forum for asking about typewriters? Tim.

18 years, 11 months

Subject: AMD bit-slice machines

by bobalan＠sbcglobal.net

The Tektronix 4052 and 4054 series table top graphics computers were also 2901 based. Bob Message: 14 Date: Fri, 30 Dec 2005 18:20:30 -0700 From: Richard <legalize at xmission.com> Subject: AMD bit-slice machines To: cctalk at classiccmp.org Message-ID: <E1EsVQ6-0004lt-00 at xmission.xmission.com> Besides the Lilith Modula-2 workstation, what other computers were made from the AMD 29xx bit-slice architecture? --

18 years, 11 months

Beehive terminals

by legalize＠xmission.com

Does anyone have one? They apparently were crappy designs and tended to die fairly readily, making them hard to find. They were manufactured in Salt Lake, but I haven't seen one since I used them in Delaware around 1980! -- "The Direct3D Graphics Pipeline"-- code samples, sample chapter, FAQ: <http://www.xmission.com/~legalize/book/> Pilgrimage: Utah's annual demoparty <http://pilgrimage.scene.org>

18 years, 11 months

1802 problems

by ard＠p850ug1.demon.co.uk

Does anyone really know the RCA 1802 processor hardware? I am still debugging the microwriter, and have not got very far. I have an RCA user manual on the processor which seems quite comprehensive, I am asusming it's accurate. Now, according to that manual, the processor can be in one of 4 states (fetch, execute, interrupt responze, DMA), and which state it's in is output on 2 lines called SC0 and SC1. The INT/ line is high, both DMA IN/ and DMA OUT/ are also high. I can detect no gltiches on any of these signals. The clock is running, the bus looks active, etc. The problem is that I am getting active-high pulses on SC1. This, according to the data sheet means it's doing a DMA or interrupt response cycle. But why the heck should it? I thought it was a defective 1802 chip, but another one pulled from an old board shows identical behaviour (right down to locking up after typing 8 characters on the microwriter keyboard). I can't believe 2 have failed in exactly the same way. Unless of course this is a well-known problem. Any thoughts? -tony

18 years, 11 months

EPROM labels

by rcini＠optonline.net

All: Just a quickie.what would be a suitable replacement for the opaque labels that one would stick over EPROM windows? I was going to use electrical tape but it's so sticky and white mailing lables leave glue residue. Rich Rich Cini Collector of classic computers Build Master for the Altair32 Emulation Project Web site: http://highgate.comm.sfu.ca/~rcini/classiccmp/ /************************************************************/

18 years, 11 months

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test-drb December 2005