Search found 145 matches

by marcelk
14 Feb 2019, 21:19
Forum: Escape Meta Alt Control Shift
Topic: VCF Pacific Northwest 2019
Replies: 0
Views: 15

VCF Pacific Northwest 2019

It's not listed on the VCF website yet, but today we received confirmation that we can exhibit at the Vintage Computer Festival PNW 2019! Date : The weekend of March 22-23, 2019 Location : The awesome Living Computers Museum+Labs , Seattle, WA Because : Why not...? It will be awesome...! Space_Needl...
by marcelk
12 Feb 2019, 10:57
Forum: Hardware and software hacking
Topic: Expansion bus
Replies: 11
Views: 633

Re: Expansion bus

Thanks, that's great news, it removes the potential roadblock. It makes a lot of sense that it should work in practice, but still...

Now there's a clear but long road ahead, SDcard support will take quite a bit of effort.
by marcelk
12 Feb 2019, 09:51
Forum: Kit assembly
Topic: Kit assembly by Ben Heck
Replies: 0
Views: 37

Kit assembly by Ben Heck

Believe it or not, Benjamin Heckendorn (of Ben Heck Show fame) hasn't really retired from making videos yet. Today he published one where he's soldering a Gigatron... Bob Ross style! YouTube link: https://www.youtube.com/watch?v=RmHNxG9Xvew I think it's pretty neat how he explains what every part do...
by marcelk
11 Feb 2019, 14:54
Forum: Hardware and software hacking
Topic: The effect of R17 (68Ω)
Replies: 0
Views: 43

The effect of R17 (68Ω)

Today I characterised the effect of the 68Ω resistors on the video output. Their purpose is to give some form of termination. We more or less copied these from a design on the Arduino forum, without much additional thought. Of course, in the Gigatron, the game controller shares these lines, so emiss...
by marcelk
10 Feb 2019, 17:12
Forum: Hardware and software hacking
Topic: Going back to early 1975
Replies: 4
Views: 540

Re: Going back to early 1975

That is pretty cool, if you get a chance could you post a CRO screenshot of some zoomed in signals, original TTL vs HCT; would be great to see a comparison. This was still on my todo. Reality is, I didn't have a 74HCT-based Gigatron any more. All my boards were populated with non-standard chips. Al...
by marcelk
02 Feb 2019, 22:58
Forum: Hardware and software hacking
Topic: EEVblog #1176
Replies: 0
Views: 99

EEVblog #1176

In case you missed it, Dave Jones released an awesome episode today on near field emissions using his self-made 4-layer Gigatron as a teaching tool! https://www.youtube.com/watch?v=crs_QLuUTyQ Screenshot.jpg Now these's hope that I'll get mine to sing "Daisy" in the same way the Altair 8800 could......
by marcelk
20 Jan 2019, 16:26
Forum: Hardware and software hacking
Topic: Pluggy McPlugface PS/2 adapter is available
Replies: 10
Views: 651

Re: Pluggy McPlugface PS/2 adapter is available

It seems we're in good company with this solution. This is what I spotted recently on E-bay:

photo_2019-01-10_19-24-36.jpg
photo_2019-01-10_19-24-36.jpg (69.13 KiB) Viewed 46 times
Apple-II-and-II-plus-PS2-Keyboard-adapter-_1.jpg
Apple-II-and-II-plus-PS2-Keyboard-adapter-_1.jpg (18.59 KiB) Viewed 46 times
by marcelk
20 Jan 2019, 16:05
Forum: Hardware and software hacking
Topic: Gigatron Emulator for Mac OS X (first test version)
Replies: 1
Views: 93

Re: Gigatron Emulator for Mac OS X (first test version)

Thanks for sharing the source and the ready-to-go app itself. I just pulled both into the main repo. After upgrading to Mojave I managed to run it. It is very cool work, thanks so much. I like the RAM-as-graphics viewer. Especially with Racer, where it reveals how little goes on under the hood :-)
by marcelk
15 Jan 2019, 15:42
Forum: Hardware and software hacking
Topic: Expansion bus
Replies: 11
Views: 633

Re: Expansion bus

Yes, but I like to go below 100 kHz in an attempt to keep VGA alive. Will that work? What can be reason/source/justification for that apparent SD card limit of 100 kHz? Handwaving or real?
by marcelk
14 Jan 2019, 23:28
Forum: Hardware and software hacking
Topic: Expansion bus
Replies: 11
Views: 633

Re: Expansion bus

I've found the attached SPI and SD card explanation online . The software stack to make the FAT file system accessible will be a substantial effort. But it will be worth it, and with a bit of planning we can make the EPROM contents appear as a file system as well. A bit more worrisome is the stateme...