Search found 9073 matches
- Thu Apr 11, 2024 3:52 pm
- Forum: 8 BIT CORNER
- Topic: OSI 600D Superboard Build
- Replies: 366
- Views: 57383
Re: OSI 600D Superboard Build
That 48 char mod makes it look so much better. Yeah, it is soooo much better. The only issue is that the left hand margin is controlled by a value set in ROM, and if I swap to a different display, the margin is off the left hand side. I can do different ROMS that work with different displays, but i...
- Thu Apr 11, 2024 1:57 pm
- Forum: MEMBER BLOGS
- Topic: General Stuff(tm)
- Replies: 1759
- Views: 331353
- Thu Apr 11, 2024 11:18 am
- Forum: 8 BIT CORNER
- Topic: OSI 600D Superboard Build
- Replies: 366
- Views: 57383
Re: OSI 600D Superboard Build
And the 24/48 mod is now permanent
And working great
And working great
- Thu Apr 11, 2024 11:10 am
- Forum: MEMBER BLOGS
- Topic: General Stuff(tm)
- Replies: 1759
- Views: 331353
Re: General Stuff(tm)
The zeners and power jack socket should be arriving today. I have some vero board I can use to make up the little PCB for the (7.5V) power distribution, three zeners, diode to stop the Mac Portable trying to back-power the unit if the power's switched off, oh and connecting the ammeter. Once I've w...
- Thu Apr 11, 2024 9:38 am
- Forum: 8 BIT CORNER
- Topic: OSI 600D Superboard Build
- Replies: 366
- Views: 57383
Re: OSI 600D Superboard Build
It is isn't it
- Thu Apr 11, 2024 9:25 am
- Forum: 8 BIT CORNER
- Topic: OSI 600D Superboard Build
- Replies: 366
- Views: 57383
Re: OSI 600D Superboard Build
A quick aside, one of the guys over on Osiweb.org has created a new monitor ROM that allows for 48 columns as well as 24, selectable at boot time. As well as the new ROM, there is a small bodge, represented by a jumper wire here: IMG20240411085229.jpg And the results are great: IMG20240411085334.jpg...
- Wed Apr 10, 2024 11:26 pm
- Forum: MEMBER BLOGS
- Topic: Raven. A homemade Atari-like computer
- Replies: 45
- Views: 3892
- Wed Apr 10, 2024 2:51 pm
- Forum: 8 BIT CORNER
- Topic: OSI 600D Superboard Build
- Replies: 366
- Views: 57383
Re: OSI 600D Superboard Build
I did check all the inputs and I'm sure clear was OK, but certainly worth another look.stephen_usher wrote: ↑Wed Apr 10, 2024 2:48 pm Sounds like something isn't clocking in the data on the 74LS76, or the clear is being kept low. That would be my next point of investigation.
- Wed Apr 10, 2024 2:18 pm
- Forum: 8 BIT CORNER
- Topic: OSI 600D Superboard Build
- Replies: 366
- Views: 57383
Re: OSI 600D Superboard Build
How are you getting on with the tape interface? Well, not got any further, I replaced the IC but no different. I lifted a leg of the cap and no difference, and the cap was the right value. I also lifted the leg on the resistor before the cap and the value is correct and with the leg lifted the sign...
- Tue Apr 09, 2024 10:44 pm
- Forum: MEMBER BLOGS
- Topic: General Stuff(tm)
- Replies: 1759
- Views: 331353
Re: General Stuff(tm)
Yeah, three 5W Zeners is 15 watts, that's over 2 amps at 7.5V. The current limiter would kick in well before that and bring the voltage down. Therefore three Zeners is overkill a bit but it's best to engineer for the worst case. Belt and braces is always a good plan. Under test with the bench power...