Recent content by ryaninspiron

Was mostly going based off the page stating that Rev A boards (which I have) are etch jumpered for 2716 EPROMs, so I do not have any jumpers of my own on X2. It looks like the schematic shows the etch jumpers bringing pin 2-7 (EPROM pin 21) going to 5v, I can double-check that, though I haven't...

A bit of a mystery here, A while back I received an SBC200 that did not give any serial output. Shortly after, I was given a dual port ram EPROM emulator kit that a friend of mine designed, and when I load that with SDMON v3 (original monitor) and plug it into the first EPROM socket, the SBC...

Thank you very much👍 Being about 10 years too late would be right in the spirit of retro computer collecting after all. I appreciated the fast response.

I've got an open schedule all day (9/14/23) here in Dallas after a trade show wrapped up, knowing that there's no such thing as computer reset anymore, I'm wondering if there's anything of note I could see or do related to vintage computers while visiting here from New York? I don't suppose...

I would love to buy two of these, I imagine it would be great to let me back up data on my Stacy along with getting new games onto it.

So l have lots of responses and some new questions. Thanks for the input. So first of all here is my two days of responses all in one: glitch, very cool, good to know I can use that other CPU and that I can test my other ZPU boards in a functional machine for a change. Glad to hear about that...

Wow thanks for the great feedback guys, I had a very exciting morning but its all good news so far. I think I will refer to the two machines as #1 and #2 for now. IMSAI #1 has a regular cord and is only missing three switch caps I moved them over from #2. I may just keep #1 all original parts...

Hello all, I am the proud new owner of two IMSAI 8080s and I have several questions about what to do next. I have had a Cromemco system 2 before this but was never able to get it running possibly due to high levels of oxidization and broken/non functioning tantalum caps that need replacing. I...

no problem I have been swamped at work the last few days giving me little free time last week. The problem is I dont have continuity across the any of the distributer contacts, I think that the problem is the connection from the carbon brushes to the plates, I dont know if all the connections...

Q1 seems fine from what I can tell also here are a some better pics of the board this is the transistor area backlit and the trace side and here is the card at a better angle for reading the lower labels on the transformer side of the rectifiers I used AC and on the rest of the card I...

Here is the schematic with my measured voltages why does this card stay fully powered when the machine is "off"?

Just checked it and the h bridge visually appears to reset after each key press. No current in local mode. I just noticed that the selector magnet driver card is clearly having serious issues, resistor r8 is heating up to 250 degrees Fahrenheit in just about a minute of the machine running and...

:lol:, I realize that I could have picked better words but I was at a loss at the time.(I updated the post now that I know what its doing) Since yesterday I have been reading the manual and the theory of operation section in particular, it is amazing how much detail it goes into. Thanks to that...

Hello, I just picked up an asr-33 and it won't stop printing a null character.(ascii 0x00 to be exact) I took a video of the problem to save time of trying to explain it. http://www.youtube.com/watch?v=ODdcUSgReYM the only time it does anything different is when I hit the "here is" key. any...