RE: Rescue update: DEC RC-25s + / was Re: DEC cartridge ID
> Three RC-25 drives with a dozen-or-so cartridges. We know at least one drive works. If you actually get an RC-25 drive working, I'd love to hear about it. I have three RC25s (one actually in my 11/725 and two spares) and none of them work. They were never very reliable drives, even when brand new, and are possibly the worst drives DEC ever made. Fortunately for an 11/23 or 11/83 there are lots of alternative drives available. Bob
Re: Datasaab D12
On Mon, Jun 01, 2015 at 07:17:34AM -0700, Lee Courtney wrote: > Hej Pontus - > > Very, very nice. I'm sure you already know this but there is a Nordic > computing history group on Facebook, somewhat active, that may be of help. > Link: https://www.facebook.com/groups/HiNC4/ I did not, I'll take a look. > > And a group of former Datasaab employees (based in Linköping?): datasaab.se > I have met some of them in person, nice fellows. I'll certainly ask there. As well as the Facit museums (two at least). > Good luck, keep us posted on progress. Will do. > > Lee C. > > On Mon, Jun 1, 2015 at 1:18 AM, Pontus Pihlgren wrote: > > > Hi > > > > Yesterday I picked up a Datasaab D12. Which I didn't know > > existed until then. Pictures here: > > > > http://imgur.com/a/vPTZw > > > > It's a small desktop computer intended for small business > > accounting and invoicing. It's built arround an intel 4004 and > > has room for expansion cards for memory and "customer roms". > > > > The service guide mentions a "two level" environment with a > > "basic" level and a "customer program" level. I'm hoping it > > means there is a Basic interpreter but I'm not convinced. The > > manual also mentions a "D12 assembler" as the develoment > > environment. It's apparently a subsystem that comes in a nice > > attache case: > > > > http://imgur.com/QQUrcGh > > > > It's actually made by Facit and may go under that name. > > > > Does anyone know more or have manuals? > > > > Regards, Pontus. > > > > > > -- > Lee Courtney > +1-650-704-3934 cell
Re: Datasaab D12
Hej Pontus - Very, very nice. I'm sure you already know this but there is a Nordic computing history group on Facebook, somewhat active, that may be of help. Link: https://www.facebook.com/groups/HiNC4/ And a group of former Datasaab employees (based in Linköping?): datasaab.se Good luck, keep us posted on progress. Lee C. On Mon, Jun 1, 2015 at 1:18 AM, Pontus Pihlgren wrote: > Hi > > Yesterday I picked up a Datasaab D12. Which I didn't know > existed until then. Pictures here: > > http://imgur.com/a/vPTZw > > It's a small desktop computer intended for small business > accounting and invoicing. It's built arround an intel 4004 and > has room for expansion cards for memory and "customer roms". > > The service guide mentions a "two level" environment with a > "basic" level and a "customer program" level. I'm hoping it > means there is a Basic interpreter but I'm not convinced. The > manual also mentions a "D12 assembler" as the develoment > environment. It's apparently a subsystem that comes in a nice > attache case: > > http://imgur.com/QQUrcGh > > It's actually made by Facit and may go under that name. > > Does anyone know more or have manuals? > > Regards, Pontus. > -- Lee Courtney +1-650-704-3934 cell
Re: 8-bit Computer TV Channel Use
On 2015-06-01 20:24, Mark J. Blair wrote: > I'm also working on getting design details from Silicon Labs for one of their > inexpensive single-chip TV tuners under NDA. If the Crazy Cat Lady project > moves forward, that chip might come in handy. If I use that chip, I'll need > to consider whether the NDA terms would preclude me from sharing my own IP > that uses the chip, since I'd prefer to share my schematic and firmware. But > if the NDA would disallow that, then I'd either need to close part or all of > my design, or pick out a different tuner option. As far as the crazy cat lady project, as I was trying to explain earlier.. my $.02 which maybe redundant to your own thoughts: VIDEO ADC/DECODER You can certainly use an off-the-shelf part as there are 47 from 5 companies on Digikey alone in solder friendly packages. However if the classic machines you are targetting are producing a clean conforming NTSC_M/J, PAL_B/G/N, or SECAM signals, stock video decoders on most converter boxes would work perfectly already. I doubt you will have much luck with the NDA process explaining a hobby cause but worth a try. Even if you are successful, make sure the parts you are looking at are readily available in 10s and 20s quantity through a distributor chain at a reasonable cost. That may be a second hurdle if it's fairly exotic. What SiLabs part are you looking at? I can't find any recent video decoder offerings. GENERIC ADC/DSP ANALYSIS This is the harder path to go down. You will need a symbol rate of at least 54 Mhz from a single or two interleaved ADCs to have a shot at at least 50% phase accuracy (NTSC = 13.5 MHz). There are some relatively inexpensive options, but I suggest getting a lot of input from folks and other reference designs on the best way to build an analog front-end for composite. And only do composite/S-Video. There are already commodity solutions for stepping down broadcast RF frequencies to base-band. After that, you will need something fairly hefty at the start to find the characteristics of the signal and align the sampling. Then you just need to track clock drift and adjust a VCXO. Straight-forward in hardware, but I doubt many people will have the experience to add new software support for and fix bugs when they occur. So set expectations on your time early with respect to project support. SOC/ZYNQ/MARKET The fact you mention ZynQ throws up a few warning flags for me. It's probably overkill, it's expensive in low quantities through normal distributors, and it's not very hobby friendly. $65 for a '010 alone + DDR3 + BGA assembly would drive the resulting cost for you to make these boards well beyond $200. And your market is small - vintage computing folks w/o a CRT on a limited budget. Considering that, you probably should not try to build the processing core yourself. Run the ADC output or the video decoder Bt.656 output into a stock board like a Parallella, BeagleBone Black, or other EVM that has the processing power, HDMI output, and input interfaces you need; especially to start with. Then go full custom later. -Alan
Re: 8-bit Computer TV Channel Use
On Monday (06/01/2015 at 07:39PM -0700), Mark J. Blair wrote: > > > On Jun 1, 2015, at 19:31, Chris Osborn wrote: > > This one looks exactly like yours, but it’s even cheaper! I wonder if it’s > > the same? > > > > http://www.amazon.com/dp/B009A6PJKQ > > When you get it, we can compare pictures of their innards. Mine has a PCB > with blue soldermask. Most of the functionality appears to be in a single > QFP, probably with a central ground/heat slug based on the vias on the bottom > side of the board. The top of the chip appears to have been sanded to remove > the markings. I ordered one too after seeing your pictures. It seems like the Amazon price is not exactly deterministic-- I got mine for $11.90 yesterday and the same link today shows it at $14.48. Perhaps these are commodity priced, you know like corn :-) I will try mine with various DEC terminals, Heathkit H19/H89 and several other composite monochrome sources. Your 80 column display looked really nice. I had similar results with a GBS-82xx converter driving into a VGA LCD but I would say the text is not as crisp there likely due to the additional conversion back to analog VGA which your solution would eliminate. Chris -- Chris Elmquist NØJCF
Re: 8-bit Computer TV Channel Use
> On Jun 2, 2015, at 08:25, Alan Hightower wrote: > As far as the crazy cat lady project, as I was trying to explain > earlier.. my $.02 which maybe redundant to your own thoughts: You did inspire my choice of project name! :) > > VIDEO ADC/DECODER > > You can certainly use an off-the-shelf part as there are 47 from 5 > companies on Digikey alone in solder friendly packages. However if the > classic machines you are targetting are producing a clean conforming > NTSC_M/J, PAL_B/G/N, or SECAM signals, stock video decoders on most > converter boxes would work perfectly already. Right. It's the "clean conforming" part that I have heard is the issue, though my initial success with the first sub-$20 converter I tried makes me wonder whether the perceived desire for Crazy Cat Lady is overstated. > I doubt you will have much > luck with the NDA process explaining a hobby cause but worth a try. I also thought it was a long-shot, but they sent me an NDA to sign last week and now I'm just waiting for the datasheet. > Even > if you are successful, make sure the parts you are looking at are > readily available in 10s and 20s quantity through a distributor chain at > a reasonable cost. That may be a second hurdle if it's fairly exotic. > What SiLabs part are you looking at? I can't find any recent video > decoder offerings. The part in question is a tuner, not a decoder. It's Si2137, with 130 pieces on hand at Mouser. But for all I know, they might have bought one tray of somebody's leftover production parts, with no more to appear. If I use the part, I'd consider putting the tuner on a separate board with the expectation that the Si2137 might dry up without warning. > GENERIC ADC/DSP ANALYSIS > > This is the harder path to go down. You will need a symbol rate of at > least 54 Mhz from a single or two interleaved ADCs to have a shot at at > least 50% phase accuracy (NTSC = 13.5 MHz). There are some relatively > inexpensive options, but I suggest getting a lot of input from folks and > other reference designs on the best way to build an analog front-end for > composite. Definitely a learning curve here, and I will welcome input on the analog front end. > And only do composite/S-Video. There are already commodity > solutions for stepping down broadcast RF frequencies to base-band. Right. I'm looking at a $2.30 commodity part for the tuner, which is probably 1/10 the cost I could roll it myself. But having a tuner is an important feature, as most of the computers I'd want to target have RF/TV outputs, and I'd want to support them without requiring modifications to pull out composite. > After > that, you will need something fairly hefty at the start to find the > characteristics of the signal and align the sampling. Then you just need > to track clock drift and adjust a VCXO. I was wondering whether I could get away with tracking the clock drift digitally rather than closing an analog PLL. What do you think? > Straight-forward in hardware, > but I doubt many people will have the experience to add new software > support for non-standard composite output here> and fix bugs when they occur. So set > expectations on your time early with respect to project support. My expectation would be that I would make the design open, but then be very surprised if anybody rolled their own improvements rather than making sad puppy eyes and asking me to add support for their favorite neglected computer. :) > > SOC/ZYNQ/MARKET > > The fact you mention ZynQ throws up a few warning flags for me. Understood! > It's probably overkill Certainly. > , it's expensive in low quantities through normal > distributors, and it's not very hobby friendly. $65 for a '010 alone + > DDR3 + BGA assembly would drive the resulting cost for you to make these > boards well beyond $200. Agreed. But I do use them in my day job, so there's a strong familiarity factor. And another thing that I find compelling is that pushing FPGA + firmware updates would consist of instructing users to place one or more files on an SD or MicroSD card, rather than buying a programmer cable and installing a vast FPGA development platform, without me needing to roll my own FPGA reconfiguration solution. If I rolled my own with a cheaper FPGA + microcontroller, it might end up cheaper in BOM cost, but maybe not by a large margin. And one of my challenges would be for me to try to get the BGA routed on a 4-layer board by careful selection of unused I/O pins and the largest-pitch package available. It's not uncommon to use 16 layers to escape those beasts with all pins used (and I've done it myself, on more cost-insensitive designs), but that wouldn't fly for this product. I won't know if I can do it until I try. It's promising that there are Zynq 010 dev boards in the $100 range. -- Mark J. Blair, NF6X http://www.nf6x.net/
Re: 8-bit Computer TV Channel Use
I just noticed that the Si2137 and Si2177 tuners are now marked as "factory special order" and Mouser, where they were previously just marked "New at Mouser". So my guess that those parts are a leftover tray with questionable future availability might be unpleasantly accurate. I'm still interested in pursuing a cheap tuner design to see if it goes anywhere. Even if it turns out that some existing composite to HDMI converter satisfies everybody, I think there would be interest in a small, inexpensive standalone RF demod to get composite video out of vintage home machines without internal mods, and Crazy Cat Lady could morph into that. Maybe it would involve custom hardware, maybe it would be a TV tuner dongle operated in SDR mode plugged into a Beaglebone with custom software, maybe it would be a general purpose SDR design that happens to be well-suited for video demod... figuring that out is the fun part for me. -- Mark J. Blair, NF6X http://www.nf6x.net/
Re: 8-bit Computer TV Channel Use
On 2015-06-02 11:47, Mark J. Blair wrote: >> After that, you will need something fairly hefty at the start to find the >> characteristics of the signal and align the sampling. Then you just need to >> track clock drift and adjust a VCXO. > > I was wondering whether I could get away with tracking the clock drift > digitally rather than closing an analog PLL. What do you think? For the general ADC route, I would put a PLL/clock synth on the board in-case you have gross alignment errors on the incoming signal. The input should be a multiple of 13.5 but you never know with clock short-cuts on early systems. It's been a while since I've looked at the Zynq PLLs, but usually they aren't designed for large bit depth M and Ns. You will need one anyway to generate a 12.288 for audio and the different output dot clocks. I've used TI CDCE906 and IDT's VersaClock IIIs for this in other projects. A VCXO is probably the simplest choice for clock recovery. Simple PWM and RC filter to the tracking pin will allow you to slew the clock 150ppm or so. As far as ZynQ, I would throw up a few warnings about the 300 MHz DLL drop-out point on DDR3 and difficulty of routing. However I'm reminded of the Zed board and their placement of by-pass caps in a pattern that looked 'pretty'. Certainly not a beginner project, but you don't sound like one. If you wanted to start with Parallella boards instead, I have a couple trays of the SamTech mating connectors. I can send some your way. For SoC, it depends on the power you need to look at the signal. If I were faced with the requirements you have created, I would start looking at the Atmel SAMV7x line. The EVMs are starting to ship publicly and it's the first to market for the ARM M7/Pelican core. It's has more DSP performance in a small micro than most DSPs a generation ago. With OTG and integrated highspeed USB PHYs, you could also ship the frame buffer updates to a PC and support USB stick firmware update. Might be a nice alternate solution to HDMI scaling. And it's super cheap. A number of smaller FPGAs might do the trick depending on how complex your RTL pipe-line is. The usual suspects, Spartan 6, MachXO2, and the new MAX10 from Altera. -Alan
