Recent content by BJeffway

Excellent, thanks!

Excellent idea!!! Let's do it!

Hi Monty, Wow, that's very cool about your 4054A at VCFWest and the Computer Museum! You raise an very interesting point about the RAM - maybe I have had a bit or two bad and that is why my micro-code isn't working correctly, and now a bit more has gone bad. I didn't realize the micro-code...

Thanks for checking in! I got tied up with my day job, and working on my taxes! Man what a bummer when that stuff gets in the way of fun! Now that all my ROMs are checked and the one bad one replaced, I have a theory that there is a problem with address decoding. I have an instance whereby...

Hi Monty, Thanks once again for the perfect documentation! I will try that jumper tomorrow, and you gave me an idea - I should check my 5 volt supply. I see on Facebook you have been continuing to improve your asteroids game. Thanks, Bob

Hi, Not sure why that didn't work. I just tested it with those files and it worked for me, but I unzipped it and selected the .brd file. I don't know how to make the gerber or kicad files, but I just made it a shared project and this link should allow you to order them...

Hi, I took the general design from coredump, and I laid out a board in Eagle. Got 3 from OSHPark for $4.25 with free shipping. Soldered one up and it works great. Pictures and Eagles file attached. If someone needs one, let me know, I would be happy to send you one. Note the wrong checksum...

Hi, I took the general design from coredump, and I laid out a board in Eagle. Got 3 from OSHPark for $4.25 with free shipping. Soldered one up and it works great. Pictures and Eagles file attached. If someone needs one, let me know, I would be happy to send you one. Note the wrong checksum...

Hi Jos, $150 isn't cheap, but looks like I will have to make PCB adapters, buy the EEPROM, buy a newer programmer to program it, so not too bad when you look at the whole picture. I don't have a programmer for the 82S181 though. I am thinking I should just bite the bullet and make the adapter...

Hi Monty, I was going back and re-reading some of the previous posts, and I noticed you said this came from "The Technical Data Service Manual". At first I thought you were referring to the Service Manual with Schematics, but then I went looking for Technical Data Manual. WOW what a great...

Hi Dave, Thanks much for the link, I sent him a reply asking if he would share the gerber files - otherwise, I will make a board myself and share the files. So I guess it is safe to assume that trying to get a blank 82S181 and programming it isn't a realistic idea? I didn't find any, and then...

Hello, I saw this post where you made an adapter board to replace the 82S181 PROM with a modern AT28HC64B-70SU EEPROM. Excellent job, very nice! This is just what I need because I have a bad 82S181 on my Tek 4054. Do you still have the gerber files and would you be willing to send them to...

That sounds right that they would have to be fast. Man 70ns is pretty fast for 1980. I will wait to see if Jos or anyone has a solution to replace a ROM. I could probably make a board but seems like someone must have done it already.

Gentlemen, Thanks much for the above info, it was all very helpful. So, I now have some hard info on a real error. I read all my uCode ROMs, and checksums match on all but one. U340 has errors as compared to 160-0338-00. Locations $26D, $26F, $2EC, $2EE, $322 AND $3A4 have 1 bits in places...

Thanks for the very quick reply that looks like what I need! Didn’t have time to work on it yet had to meet wife at flower show!