test-drb October 2010

test-drb@ccmp.vtda.org

175 participants
274 discussions

by jonnosan＠gmail.com

I am continuing my exploration of the SacState 8008 boot PROM code (using James Markevitch's listing), and have a little more understanding of the escape codes I was asking about previously (in the thread 'identifying terminal by escape codes') It looks like the SacState machine was built as a card that plugged into a 4023 terminal motherboard. My current assumption is the data going out of the 8008 card (i.e. where the code on the PROM is running) is interacting with the other cards on the 4023 bus directly. My further assumption is that there must have been some kind of block device (tape or disk?) that was also on that same bus, and that some of the escape codes must be doing some sort of device selection (i.e. signalling that the next chunk of data is intended to be read from, or written to, a specific device, not read from keyboard or displayed on screen). I am not clear as to whether the other devices are interfacing via - a commercial 'dedicated' I/O card, e.g. a drive controller (if any existed?) - a commercial 'generic' I/O card, e.g. a serial I/O and an 'intelligent' device is being controlled - a custom made I/O card that plugged directly into the 4023 bus The only 4023 documentation I can find online is the User Manual, which has: - a list of bus signals, which confirm there are enough signals available to construct complex device I/O - a list of accessory cards, including a serial 'Data Communications Interface', a 'hard copy unit', and 'audio recorder card' (tape controller ). - a reference to a 4023 service manual, which has a 'theory of operation' which may describe enough of the bus protocol to work out how the 8008 PROM could be interacting with other devices on that BUS. So my questions are - - were any commercial accessory cards available for the 4023 other than the ones listed in the back of the user manual? If so, does any documentation for them exist? - is the 4023 "service manual" available through any means? Cheers Jonno

13 years, 5 months

Tangential to Topic: Old Chip Programmers Work w/ || Port in Docking Station?

by trag＠io.com

I have a Needham EMP-30 chip programmer. I've been keeping an old Pentium (mumble) computer around to drive it (vaguely on-topic since it's definitely more than 10 years old). It has a parallel port interface. I would like to replace the ancient behemoth computer with a notebook to save space. I would also like to buy a modernish laptop to run things like FPGA and Microcontroller development/interface systems. I'd like them to be the same laptop, so right there I'm looking at USB and parallel port on the same notebook. Looking around, that does not appear to be available in new products. Ordinarily, I don't shy away from used equipment (who does, on this list?), but for notebooks, with their breakage issues and such, I would prefer to buy new. Further shopping revealed that Dell sells a Legacy Port Expander which works with some of their current notebooks and provides serial and parallel ports. And I think I've read somewhere while searching that the Needham software will work with Windows XP (could be mistaken, need to search again). Do any of you know if chip programmers (the EMP-30 specifically) work okay with the parallel ports in port expanders? How about the Cardbus (or whatever is replacing it) parallel port cards? Alternatively, anyone go through this exercise already and pick out what seemed like the ideal notebook model with USB and parallel ports. I might consider a used model if someone has a strong recommendation. Thank you for any discussion, Jeff Walther

13 years, 5 months

seeking DEC digital mps - microprocessor series monitor/control panel

by nigel.d.williams＠gmail.com

http://www.dvq.com/oldcomp/photos2/1k/dec_micro_panel.JPG I find this device quite fascinating (Intel 8008 plugged into a PDP-8 host), if anyone has one surplus I would be interested in negotiating. thanks. www.retroComputingTasmania.com

13 years, 5 months

DiscFerret: First working hardware, firmware and microcode!

by classiccmp＠philpem.me.uk

Hi guys, I have -- just this second -- got the standalone, single-board DiscFerret hardware ("0I06") to image a disc. First, the proof: Scatter plot: http://www.discferret.com/temp/dat.scatter.png Histogram: http://www.discferret.com/temp/dat.histogram.png Raw transition data, gzipped space-separated format. First column is array index, second column is the timing value: http://www.discferret.com/temp/dat.gz Rawbinary track dump, gzipped. Most significant bit of each byte is the status of the INDEX sensor (1=index detected). If (x&0x7f) = 0, then a counter carry occurred -- the next byte should have 128 added to it. Repeated counter-carries are allowed.: http://www.discferret.com/temp/dat.bin.gz MagScan analyser output for dat.bin: http://www.discferret.com/temp/dat.magscan.txt For those of you who have a copy of the sources to my Magdecode decoder engine (I know I sent it to at least one person on-list...), the Rawbinary dump should load straight into Magdecode. The space-separated data can be loaded straight into Gnuplot (which is what I used to produce the plots), and I suspect MATLAB and Octave can probably load it too. The image file was created from an old coverdisc from "PC Zone" magazine, and is completely undated on the label. The volume label is "PCZ_OCT_3" which suggests it's from October, with last-modified dates in February and August 1993. It only covers Track Zero, which (if memory serves) is the MBR, FAT and Root Directory. The disc is 720K DOS format, sampled at 40MHz. Other things to note: - The hardware works fine at 80MHz, and possibly faster than that. It should be possible to sample with enough resolution to image a 5Mbps MFM hard disc. - There are plenty of spare registers. The new PIC uses 8-bit multiplexed addressing, which gives 256 register addresses. Only 16 are in use at the moment (!) - Write support isn't enabled yet. I need to port this across from DiscRW and test it (and no doubt rewrite parts of it, as I did with the reader engine). Surprisingly, there are only a few minor issues on the 0I06 PCBs: - C6 is missing a polarity marker. This is a non-issue, as one end connects to the ground plane and the other quite obviously connects to +5V. - Some of the component pads are rather small (notably the inductors and Schottky diodes in the power supply). This makes it hard to heat both the pad and the component pin at the same time, and thus makes the parts a bit of a pig to solder. I worked around this with a hot-air gun, preheater and solder paste... later boards will have bigger pads. - The power supply chip is a QFN with pads under the chip. The only way to solder it down is to use a hot-air gun... unfortunately TI don't make this chip in a more accessible package, and the only viable alternative would have nearly doubled the size of the power supply. Despite these issues, it's perfectly possible to assemble a 0I06 and have it work perfectly, without any "green-wire" fixes. I'm impressed: usually a first-spin board needs at least one track-cut and a couple of green-wires :) Now here's where you guys come in. I really don't want to have boxes and boxes of unused boards and parts hanging around, so I need to know how many people would like to buy a DiscFerret. These would be available as: - PCB only - PCB with the power supply section assembled and tested - Fully assembled and tested PCB - Some other form -- feel free to make suggestions! I'd appreciate it if anyone interested in buying a DiscFerret could email me at philpem at philpem.me.uk, with one of the following in the subject line (start, end, on its own, uppercase, lowercase -- anything will do, my procmail rule is pretty lenient): - "I want a PCB on its own" -- DISCFERRETBARE - "I want a PCB with the PSU built and tested" -- DISCFERRETPSU - "I want the whole thing ready-built" -- DISCFERRETBUILT - "I want a DiscFerret in some other form" -- DISCFERRETOTHER Thanks to everyone who has supported the project thus far -- your thoughts, ideas, comments and criticisms have been very useful! Now to get my reflow oven working and build some prototypes... :) Thanks! -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/

13 years, 6 months

TRS-80 Model II Manuals

by nathan＠nathanpralle.com

Thanks to the ever-useful JP Hindin, I've obtained a set of TRS-DOS disks and other application disks for my TRS-80 Model II system, which is the entire setup pictured here, plus a bit more: http://oldcomputers.net/pics/TRS-80-II_table.JPG It's been sitting, covered, pretty much since I obtained it, but now I can try reviving it and actually seeing what it can do. I'm going to tear into it and clean the drives and so forth, document what it has, etc. and then boot 'er up and see what we can see. I'm looking for a copy of the Technical Ref manual for it; despite finding scans of the covers and so forth online, I'm unable to actually locate one. In addition to that, if someone has a Shugart 8" Service Manual, that might come in damned handy for making sure those are up to speed as well. Many thanks, Nathan -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Nathan Pralle, Computer Geek Email: nathan at nathanpralle.com Web: http://www.nathanpralle.com Blog: http://www.philosyphia.com Twitter: http://twitter.com/NathanPralle -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

13 years, 6 months

SparcStation Voyager framebuffer problem

by IanK＠vulcan.com

I posted not too long ago looking for a framebuffer driver that seemed to be missing from the Solaris distributions I have for my Voyager. Well, I finally opened up the machine and found something quite unexpected. I had assumed (as had others, according to statements) that the color and monochrome components (screen and framebuffer) would be physically incompatible, so it would be impossible to mix and match. *Wrong!* In fact, I found I have a color framebuffer, which was talking to the monochrome screen. What's really strange is that OpenBoot seems to have created a new name - bwthree - to describe the framebuffer! I don't suppose anyone has a monochrome framebuffer with which you might be willing to part company? Or perhaps a color screen? -- Ian UNIX is user friendly. It's just selective about who its friends are. Ian S. King, Sr. Vintage Systems Engineer Vulcan, Inc. http://www.livingcomputermuseum.org

13 years, 6 months

Happy Birthday VAX 11/780 (influence of)

by bqt＠softjar.se

On 2010-10-29 19:00, "Chuck Guzis"<cclist at sydex.com> wrote: > On 29 Oct 2010 at 0:11, Johnny Billquist wrote: > >> Next question: Does the VAX not have virtual memory any more now that >> I've pointed this out? Or do you need to redefine virtual memory in >> yet a new and strange way to exclude the PDP-11... :-D > > I think that using memory address spaces to qualify the "virtualness" > of memory is following the wrong animal. I think that virtual address space is intimately connected to virtual memory, and you cannot have one without the other. If your program vrites data to address 0, and reads it back, and get the same data back, and another program on the same machine, at roughly the same time, write to address 0, and reads the same data back, and that data is different than the first programs data, then I'd say you have virtual memory. > I would define "virtual memory" as the ability to fool a program into > thinking that it has more physical memory than is actually present. > So, can a PDP-11 with 16K of memory appear to a program as if there > were 32K present? Certainly. If we just disregard that the code needed to implement this thing might need more memory than 8K. The program that we intend to fool must have atleast 8K of physical memory, to which we can read in and out pages. With 16K that would leave just 8K for out demand paging software... Well, actually, this is a bit too simplified. An instruction can potentially refer to 4 pages, so we would need to be able to have four pages to be able to fully fool a program. That would mean minimum 32K of physical memory to use for the user program. And then some for your kernel. But you'd probably be able to come in under 56K, while fooling the program that is has 64K. With less than four pages, you could get into a situation where mapping in one page means you have to map out another, which the instruction refers to, and when you restart the program you'll just get another page fault, ad infinitum... :-) Johnny -- Johnny Billquist || "I'm on a bus || on a psychedelic trip email: bqt at softjar.se || Reading murder books pdp is alive! || tryin' to stay hip" - B. Idol

13 years, 6 months

TTL HEX LED driver chip

by chd＠chdickman.com

Was there ever such a thing as a 74x00 series LED driver that did proper hex decoding and not simply BCD? I can't seem to find that there was. The topic of why split octal was used on some early micro-computers came up on a list. After doing a search for a TTL LED driver that does hex, the answer is probably that there were no single chip option for hex displays. Split octal was just easier. This kind of joins in with the TIL311 discussion. It was a TTL compatible hex display, but expensive at the time. -chuck

13 years, 6 months

Nuclear Data ND 6600

by legalize＠xmission.com

The Nuclear Data ND 6600 was some sort of laboratory PDP-11 setup. I have a terminal from such a system (very nice green keyboard). I'll upload some pics this week. However, while I was packing up the stuff I bought at the vendor's store, I saw that he had the rest of the system and not just the one terminal. Looks like a couple other terminals, some characteristically PDP-11 enclosure boxes (2x floppies, some other stuff, power enclosure). It looks like this stuff was meant to be rack mounted, except for the terminals, because there's no typical DEC enclosure like I would expect. Googling doesn't turn up anything useful except the usual firewalled citations from IEEE and ACM journals containing product announcements. Does anyone know more about these systems? From the descriptions that leak through google, it appears that it might have had some graphics capability and that interests me quite a bit. I couldn't look at the system close up because it was on a huge pile of stuff and I didn't have time to dig it out. -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/> Legalize Adulthood! <http://legalizeadulthood.wordpress.com>

13 years, 6 months

Large geometry MFM drive testing

by snhirsch＠gmail.com

All, I'm trying to evaluate a pile of large MFM hard drives for functionality. I'm attaching them to a WD-1006V-MM2 controller and running Sprinrite 4 under DOS 6.0 (using a 486 EISA motherboard). This works fine for drives with < 1024 cylinders, but I cannot seem to remember (or figure out) how to surface-test drives with more cylinders (e.g. Priam V185 with 1166). How do folks on the list test these beasts? I've seen SCSI controllers and ESDI controllers with CHS translation, but that feature does not seem to be available on the MFM adapters. Steve --

13 years, 6 months

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test-drb October 2010