Search found 237 matches

by Mr Nours
Fri Jun 19, 2020 1:28 pm
Forum: 680x0
Topic: ROM address map
Replies: 3
Views: 211

ROM address map

Hello Guys,

Do you know if there is somewhere an address map of the ROM?

I want to get the bee bitmap or the system font for a basic scrolltext but i don't find any related document.

Does the address of the system font is always the same between TOS versions?

Thanks :D
by Mr Nours
Thu Jun 18, 2020 8:23 pm
Forum: Hardware
Topic: RAMcart Atari ST
Replies: 4
Views: 299

Re: RAMcart Atari ST

Seems cool :D

Why 2x128k ? I tought the max size of an ST cartridge was 128k.

You could switch between two banks?
by Mr Nours
Wed Jun 17, 2020 11:27 am
Forum: Hardware
Topic: 1040 STf with scrolling problem
Replies: 6
Views: 211

Re: 1040 STf with scrolling problem

So... i changed the GLUE with another one and now all is fine. Nice scrollings!

Image

Image
The nasty defective chip.

Case resolved ! :cheers:
by Mr Nours
Wed Jun 17, 2020 9:17 am
Forum: Hardware
Topic: 1040 STf with scrolling problem
Replies: 6
Views: 211

Re: 1040 STf with scrolling problem

@tzok Yes! It is cool, almost all chips are socketed :) I replaced the C10019-001 MMU for a C025915-38A this morning. But the scrolling problem persists. So : - memory tests are OK - MMU replaced ( from afaulty motherboard which has RAM issues ... perhaps try one wich is known to work ) - Shifter r...
by Mr Nours
Tue Jun 16, 2020 9:01 pm
Forum: Hardware
Topic: 1040 STf with scrolling problem
Replies: 6
Views: 211

Re: 1040 STf with scrolling problem

@DoG, tried several times ant it always show this bug whit several games an demos..

@alien
Thanks! i didn't know that. Il will try to reseat or replcae the MMU ( labelled C10019-001 here, seems an early model no? ).

Nrs.
by Mr Nours
Tue Jun 16, 2020 8:23 pm
Forum: Hardware
Topic: 1040 STf with scrolling problem
Replies: 6
Views: 211

1040 STf with scrolling problem

Hello! I had a strange problem with a 1040 Stf motherboard. All hardware tests via the cartdrige cart seems fine ( timing, ram, rom etc ), i can even load games and demos but when there is a scrolling, the screen goes corrupted. I had tried to change the shifter, with no effect. The motherboard : ht...
by Mr Nours
Fri Apr 10, 2020 11:28 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

Hello, I made a complaint to the seller who promise me to send me the right chip. But i received the ten ones before... So as I had received the new chip , i removed the old one with bad ref and put the new 74S257 ( ref : SN74S257N ) in his socket. and... Booted with a a mono screen : https://i.imgu...
by Mr Nours
Mon Mar 16, 2020 12:15 am
Forum: Hardware
Topic: 1040 STF motherboards with ram errors
Replies: 6
Views: 647

Re: 1040 STF motherboards with ram errors

deleted
by Mr Nours
Mon Mar 16, 2020 12:13 am
Forum: Hardware
Topic: 1040 STF motherboards with ram errors
Replies: 6
Views: 647

Re: 1040 STF motherboards with ram errors

Thanks for the schematics.

I socketed and changed U11 :)

Now i get something new:

Image

Should i read that as " Change U3 & U10!" ?

U3 is socketed... with a new chip :roll:
by Mr Nours
Sun Mar 15, 2020 9:14 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

Yes, I made a complaint and ordered a bunch of ten 74S257 chips on ebay.

As always i will keep you informed when i received and replaced this chip.

I hope this will be the end of this topic and a new beginning for this STe :)
by Mr Nours
Sun Mar 15, 2020 9:03 pm
Forum: Hardware
Topic: 1040 STF motherboards with ram errors
Replies: 6
Views: 647

Re: 1040 STF motherboards with ram errors

Great! Thanks to your post I think i understand how to interpret those cryptic error codes! After reading you, i realize that i was really wrong, i then found this post on exxos forum : https://www.exxoshost.co.uk/forum/viewtopic.php?f=29&t=1956 tldr : 0000000000000000 00000000000000000 Lower bank (...
by Mr Nours
Sun Mar 15, 2020 3:53 pm
Forum: Hardware
Topic: 1040 STF motherboards with ram errors
Replies: 6
Views: 647

1040 STF motherboards with ram errors

Hello, Good side of this european virus invasion is that i will have some spare time to fix some old stuff lying around. So i had taken back two 1040 STF motherboards wich seems to had the same problem. On those two boards, when booted we had some screen corruption with vertical bars, so i assumed i...
by Mr Nours
Sun Mar 15, 2020 2:13 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

Well, I had a doubt, so i had checked my last order, and i do ordered a "74S257" @ littlediode.com They send me a 74LS257 chip instead... wich seems no compatible at all... Well... do you guys know where i could order a "real" 74S257 ? Edit : Found here by pack of 10 ... https://www.ebay.fr/itm/SN74...
by Mr Nours
Sun Mar 15, 2020 1:58 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

Thanks, i understand my error! Quite dumb... bad ref.
So the poor chip sn't fast enough so it causes flickering!

Hopefully i had socketed this chip, i will then just had to order a good chip!

This one seems ok :
https://www.littlediode.com/components/74S257N.html <-it is not, this were i ordered...
by Mr Nours
Sun Mar 15, 2020 1:46 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

frank.lukas wrote:
joska wrote:
Mr Nours wrote:This is a 74LS257
It is a 74S257 or a 74F257 ...
Thanks joska, you mean that i ordered a bad reference?

The new chip is labelled DM74LS257BN, this seems good to me to replace a 74LS257... no? :shrug:
by Mr Nours
Sun Mar 15, 2020 1:23 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

Hello all, :D Some good news and some bad news... Good news is that i had received the new u405 chip... i have removed the old one, put a socket, insert the new one and fixed( see photos ) the traces that i had once cutten for testing. Liike a butcher, but seems ok with my multimeter.... Yay! The au...
by Mr Nours
Thu Feb 20, 2020 1:17 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

I agree! I will order a new chip if i found a seller. Meanwhile, i had soldered u405 pin 5 to u405 pin 7 to force the ST to boot in low res, works well. Thanks for your help, i had learned a bit about how our atari detect monitors and auto set their resolution properly. I will update this thread if ...
by Mr Nours
Wed Feb 19, 2020 1:26 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

Ok, With a cutter i cut the trace between video pin 4 and pin 2 and 6 of the u405. pin 2 and 6 has continuity with GND. Pin Video 4 has not. I cutted the link between pin 6 and 2. Pin 2 has continuity with GND, Not 6. Well, i had cutted deeper and always pin2 connected to GND. I i checked the schema...
by Mr Nours
Wed Feb 19, 2020 12:42 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

Good news here, I've tested to connect pin 5 (5v) to pin 7 and successfully boot in low resolution ( Gool ol' green desktop ). So two options : - Cut the trace to see where it is connected to GND - remove the U405 an change it ( tzok says 1.3v on ttl is a bad chip... ) What's the best? Joska, the do...
by Mr Nours
Tue Feb 18, 2020 9:58 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

Some measurement with monitor unplugged :

U405:
Pin 1 = 5.02 v dc
Pin 2 = 0v
Pin 3 = 0.924 v
pin 4 = 1,374 v
pin 5 = 5,02 v
pin 6 = 0v
pin 7 = 191 mV
pin8 = 0v

So clearly i got no 5V on pin 7.

Could i solder a wire between pin 1 and 7 to force the ST to go in low mode?
by Mr Nours
Tue Feb 18, 2020 9:21 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

Frank Lucas, the U405 is labelled as a a 74S257N...
by Mr Nours
Tue Feb 18, 2020 9:10 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

Here's the backside of the u405 area. I tested pin4 of the video connector by inserting a wire in it. I got continuity between video pin4 and u405 pin 2 and 6 and ground. Resistance between video pin4 and ground is about 1,6 Ohm. https://imgur.com/eLBQVe9.jpg If no one ha other idea, i think i will ...
by Mr Nours
Tue Feb 18, 2020 3:44 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

When pin 4 on the monitor socket is grounded, TOS use monochrome mode. If it's not grounded, TOS will only allow colour modes. Disconnect the monitor, and see if there's continuity between U405 pin 6 and ground. If there is, there's either a problem with U405 or the monitor socket. PIN 6 is grounde...
by Mr Nours
Tue Feb 18, 2020 2:46 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

Diag Cart on sm124 : https://imgur.com/LO1Qbl5.jpg On the sc1425 screen i got nothing but black screen. Same on a modern lcd screen ( "no image" ). So I blindly forced the STE to go into med res with the memory examiner. ( by typing E then W ff8260=1 ) And got this : https://imgur.com/hhKkFXw.jpg I ...
by Mr Nours
Tue Feb 18, 2020 12:08 pm
Forum: Hardware
Topic: Atari STE only boot in High Res
Replies: 45
Views: 3671

Re: Atari STE only boot in High Res

Deleted

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