Search found 259 matches

by tzok
Tue Jan 19, 2021 11:25 am
Forum: HARDWARE DISCUSSIONS
Topic: Internal drive select
Replies: 36
Views: 1431

Re: Internal drive select

Well it works without the external pull-up, so where is the problem? It was working like that for the last 30 years... Shugart' specification says that the DS line is OC, so there should be no pull-ups on the host controller side. The drive itself also doesn't have external pull-ups, but when powere...
by tzok
Tue Jan 19, 2021 10:48 am
Forum: HARDWARE DISCUSSIONS
Topic: Internal drive select
Replies: 36
Views: 1431

Re: Internal drive select

I've measured it on the actual drive. But it is logical. The Specification says that the Drive Select line (among other lines) is an open collector type, so the drive has to deal with it. One more thing - you don't need any adapters. All you need is a switch shorting and opening a jumper/shunt on th...
by tzok
Mon Jan 18, 2021 8:14 pm
Forum: HARDWARE DISCUSSIONS
Topic: Internal drive select
Replies: 36
Views: 1431

Re: Internal drive select

Controller IC in that drive has an internal pull-up of about 16kΩ. The Drive Select line on the host/controller side is supposed to be open collector. Atari is a little "noisy" so it is better to use additional pull-ups, but both options should work. SIMPLE __________ PIN 10 PIN 10 _________________...
by tzok
Mon Jan 18, 2021 5:59 pm
Forum: HARDWARE DISCUSSIONS
Topic: Internal drive select
Replies: 36
Views: 1431

Re: Internal drive select

Drives are expected to have pull-up resistors on the Drive Select lines, so there's really no need for this resistor. Yet it is safer to put 4,7k pull-up resistors on the drive sides of the switch (1 resistor for each drive). They should not be switched. Motor-On line is common for all 4 drives acco...
by tzok
Fri Jan 15, 2021 4:53 pm
Forum: ELECTRONICS
Topic: Weird capacitor marking?
Replies: 2
Views: 172

Re: Weird capacitor marking?

I'd say 100uF 6V. I'd have more doubts about the bigger one.

I've got one marked as:
70T <- date code
100 <- capacitance
6V <- voltage rating
and these are 100uF/6V.
by tzok
Wed Jan 13, 2021 11:19 pm
Forum: HARDWARE ISSUES
Topic: Dead Atari STF - C070789 - 002 Rev.D
Replies: 20
Views: 602

Re: Dead Atari STF - C070789 - 002 Rev.D

wietze wrote:
Wed Jan 13, 2021 9:21 pm
I am using RAM simms that I have succesfully tested using Yaart on another machine.
I see no SIMMs there (SIMMs are used in the STe, here you have just chips in DIP packages), but what I see is the AT-Speed hardware emulator. Have you tried removing it?
by tzok
Tue Jan 12, 2021 3:44 pm
Forum: STE V1 SERIES 32MHz BOOSTER
Topic: STE 32MHz PLUG IN BOOSTER (again) 2021 variation
Replies: 71
Views: 2593

Re: STE 32MHz PLUG IN BOOSTER (again) 2021 variation

I'd really like to help, but unfortunately I have to give up. I currently own only one STe, with external Blitter (early board, with some factory bodges), the second one, with integrated Blitter, does not belong to me, and I've verified that it has CPU soldered on the board. So I can't risk damaging...
by tzok
Mon Jan 11, 2021 8:23 pm
Forum: STE V1 SERIES 32MHz BOOSTER
Topic: STE 32MHz PLUG IN BOOSTER (again) 2021 variation
Replies: 71
Views: 2593

Re: STE 32MHz PLUG IN BOOSTER (again) 2021 variation

As far as I remember STe machines with internal (integrated) Blitter, have no socket on CPU... and I guess you won't be willing to send anything to PL ;) How fast the ROMs need to be in order to this booster work?
by tzok
Sun Jan 03, 2021 4:32 pm
Forum: NOOB QUESTIONS
Topic: EPROM chips for TOS replacement Atari ST
Replies: 10
Views: 524

Re: EPROM chips for TOS replacement Atari ST

Technically they are EPROMs, but have no quartz window, so they are called OTP EPROMS.The PROM term seems to be obsolete and reserved, for "fusible" memories.

There is a Flash EPROM replacement for 27C256 - this is Winbond W27C256 (and 27C512). Despite also being 27C marked, they are Flash EPROMS.
by tzok
Sat Jan 02, 2021 10:23 am
Forum: ELECTRONICS
Topic: Voltera printer - the beginning..
Replies: 35
Views: 3098

Re: Voltera printer - the beginning..

I'm using solder pastes available on Polish market, so don't know if you can buy them in the UK. They are Easy Print solder pastes by AG Termopasty.
I have two of these:
Leaded: Sn62Pb36Ag2
Lead Free: Sn96,5Ag3Cu0,5

Go to advanced search