Search found 2936 matches

by exxos
Wed Sep 19, 2018 12:03 am
Forum: ALPHA USER BUILDS
Topic: Icky - Progress
Replies: 33
Views: 283

Re: Icky - Progress

Cool! So we need to get your video stable more than anything next... You might even be able to try the diagnostic cart in the thing.. I mean even if you get a red screen it will give a clue how far down the ROM its getting..

Indeed a long day, we went through a lot today! :cheers:
by exxos
Tue Sep 18, 2018 11:21 pm
Forum: ALPHA USER BUILDS
Topic: Icky - Progress
Replies: 33
Views: 283

Re: Icky - Progress

OK - I found some bad soldering on the RP6. I cleaned it up and now I am getting bombs but the screen is still all over the place. Let me attach a video OK.. might be idea to measure resistance on each CPU pin and make sure you read something to VCC.. (IE 2.2K) If your using Csync on your cable the...
by exxos
Tue Sep 18, 2018 11:19 pm
Forum: STF REMAKE PROJECT
Topic: A thought for diagnostics
Replies: 0
Views: 14

A thought for diagnostics

I wonder if a new simple ROM could be done, a small loop which would basically pulse each address line one by one... .. Would probably have to wire DTACK low else it probably cause a BERR as not every address is used etc... Also probably have to hardwire ROM chip enable to gnd as we dont know if GLU...
by exxos
Tue Sep 18, 2018 11:08 pm
Forum: ALPHA USER BUILDS
Topic: Icky - Progress
Replies: 33
Views: 283

Re: Icky - Progress

Icky wrote:
Tue Sep 18, 2018 10:54 pm
Yes on start it goes from 59.9Hz to 49.7Hz on my scope
Just for hell of it, just try lifting up the ROM in the socket a tiny bit... I can only think ROM starts running then dies a few address lines up...

Do you get activity on all data & address lines ?
by exxos
Tue Sep 18, 2018 11:07 pm
Forum: ALPHA USER BUILDS
Topic: Forgottenmyname - Progress
Replies: 31
Views: 263

Re: Forgottenmyname - Progress

I think it was you who fitted the rom socket in wrong way ? That could be why your not getting as far as Icky if the ROM isn't making good contact in the socket, which I assume it isn't...
by exxos
Tue Sep 18, 2018 10:50 pm
Forum: ALPHA USER BUILDS
Topic: Icky - Progress
Replies: 33
Views: 283

Re: Icky - Progress

Icky wrote:
Tue Sep 18, 2018 8:41 pm
Right I am caught up extra SIL in place but still no joy.
Are you still seeing 50hz set on boot ?
by exxos
Tue Sep 18, 2018 10:01 pm
Forum: ALPHA USER BUILDS
Topic: Icky - Progress
Replies: 33
Views: 283

Re: Icky - Progress

I think if your switching to 50hz then TOS must be running to a point, so not long after looks to be like MMU setup, then onto RAM setup.. So might be worth checking out the RAM side of things on the PCB, and even double check what I've wired in the diagram.. I am checking things out myself, not fou...
by exxos
Tue Sep 18, 2018 9:45 pm
Forum: ALPHA USER BUILDS
Topic: Forgottenmyname - Progress
Replies: 31
Views: 263

Re: Forgottenmyname - Progress

Ok, so all three ROM1,2,3 inputs have to be high to disable the /OE on the ROM. Can you think of any reason that the GLUE is disabling the ROM? GLUE will disable the ROM when its not accessing it.. After reset you will see OE go low (or should do) because the CPU will read the first bytes in ROM to...
by exxos
Tue Sep 18, 2018 9:42 pm
Forum: NEWS & ANNOUNCEMENTS
Topic: Facebook login
Replies: 2
Views: 38

Re: Facebook login

michael.keenleyside wrote:
Tue Sep 18, 2018 9:15 pm
I've just found an image which illustrates what this feels like:

https://www.gateworld.net/wp-content/up ... argate.jpg
:bravo:
by exxos
Tue Sep 18, 2018 9:34 pm
Forum: ALPHA USER BUILDS
Topic: Forgottenmyname - Progress
Replies: 31
Views: 263

Re: Forgottenmyname - Progress

OK so probably the confusion over A16 is 6 ROM vs 2 ROMs. A16 is wired for "2 roms" but of course thats 2x8 bit roms, whereas I use 1x16bit ROM. So A16 is correct. GLUE decodes the ROM address which drives the OE (on the plcc rom) via the LS11.

So its all correct...