Search found 71 matches

by guus.assmann
Sun Sep 08, 2019 10:51 am
Forum: Hardware
Topic: need help with identifying early TT motherboard IC's
Replies: 8
Views: 2000

Re: need help with identifying early TT motherboard IC's

Hello,
According to my schematis and layout, it's U206 and that's the MCU.
Can't find the chip number right now. (The chip is below the casing for the VME-Card.)
by guus.assmann
Tue Aug 13, 2019 8:32 am
Forum: Hardware
Topic: Announcing the Lightning ST - USB & IDE for STs
Replies: 69
Views: 6006

Re: Pre-announcing the Lightning ST - USB & IDE for STs

Frank Lukas has (almost) made an adaptor like this.
It should not be difficult to change the PCB he made, to use the plug.

BR/
Guus
by guus.assmann
Sun Aug 11, 2019 10:25 am
Forum: Hardware
Topic: Announcing the Lightning ST - USB & IDE for STs
Replies: 69
Views: 6006

Re: Pre-announcing the Lightning ST - USB & IDE for STs

Thanks for the efford of making this hardware. :-) Veru curious about the price...... As for the question of IDE for all models: It would enable me to take one CF-card and use that on all models. This is a very nice way to exchange a lot of data at once. So use a relatively small card to boot from a...
by guus.assmann
Wed Jul 31, 2019 11:39 am
Forum: Hardware
Topic: The SECRET VIDEO MODE in an ST: 400 lines in COLOR (and with 72 Hz)!
Replies: 95
Views: 18466

Re: The SECRET VIDEO MODE in an ST: 400 lines in COLOR (and with 72 Hz)!

So please post those sources and the hardware schematics for it.
I'd like to see if it's usefull for me.
And the compiled usable version would also be a great plus. :D
by guus.assmann
Wed Jun 05, 2019 9:23 pm
Forum: Hardware
Topic: New board: MonSTer
Replies: 589
Views: 184715

MonSTer

Hello Alanh, I am able and willing to help out. I've build quite a number of MegaSpeedy PCB's for the Atari 8 bit. That has a Xilinx XC 95144 and I hand soldered those. The only thing that can be a setback, I'm in the Netherlands and postage is not so cheap. PM me if you see some possibilities. BR/ ...
by guus.assmann
Tue Jan 01, 2019 2:16 pm
Forum: Professionals
Topic: CF cards partioning for TT with Storm-card
Replies: 4
Views: 1558

CF cards partioning for TT with Storm-card

Some help, pointers and considerations are welcome. What I want to find out is an optimum in configuring the CF-cards that I can use on the TT. I have a number of 4GB-cards. And I would like to exchange software from a PC and maybe also with a Falcon. So the card should have a partion for PC as well...
by guus.assmann
Thu Jul 05, 2018 7:09 pm
Forum: Hardware
Topic: F030 RTC/NVRAM replacement kit
Replies: 17
Views: 2576

Re: F030 RTC/NVRAM replacement kit

Hello, A short while ago, I replaced the RTC on 4 Falcons. The RTC's came from Mouser and were sure to be new and good. But on 2 boards they didn't work, the boards would not boot with the new Clock. When the old IC was put back, it worked just fine again. However, a solution was found. The Falcon w...
by guus.assmann
Sat May 12, 2018 1:31 pm
Forum: Hardware
Topic: Broken monitor tube (glass end)
Replies: 3
Views: 1472

Re: Broken monitor tube (glass end)

Hello,

To test, just switch it on.
If it's ok, then it will work. (Obviously) :)
If the vacuum is gone, it just won't work.
Mostly, the front won't look nice and even if the vaccum is gone.

BR/
Guus
by guus.assmann
Thu Feb 08, 2018 8:52 pm
Forum: Hardware
Topic: Upgrading serial port for higher speed / more midi stability
Replies: 121
Views: 19608

Re: Upgrading serial port for higher speed / more midi stability

Hello Foxie, What I can see in the schematics is that the LDS signal is used as a clock to 74F74 FF's. A signal called SEM is delayed by one extra FF that's also clocked with the LDS. So it looks like the complete access cycle is delayed to give the Midex a bit more time to finish a cycle. Maybe slo...
by guus.assmann
Wed Feb 07, 2018 8:46 pm
Forum: Hardware
Topic: Upgrading serial port for higher speed / more midi stability
Replies: 121
Views: 19608

Re: Upgrading serial port for higher speed / more midi stability

Hello Foxie,
Yes, I did figure out (for a bit) what it does.
It inserts an extra wait-state in the handling of a command.
BR/
Guus
by guus.assmann
Mon Feb 05, 2018 8:46 pm
Forum: Hardware
Topic: Upgrading serial port for higher speed / more midi stability
Replies: 121
Views: 19608

Re: Upgrading serial port for higher speed / more midi stability

Hello, Does anyone have the MROS files from Steinberg that work on a Falcon? I've tried to modify a Midex+ to run on a Falcon. But the testprogram keeps telling it cannot find a file in the MROS folder. The modified Midex doesn't work on a Mega ST anymore. (But can be made switchable real easy.) BR/...
by guus.assmann
Sat Jan 20, 2018 8:59 pm
Forum: Hardware
Topic: Upgrading serial port for higher speed / more midi stability
Replies: 121
Views: 19608

Re: Upgrading serial port for higher speed / more midi stability

Hello Foxie, The full schematics in a four sheet PDF, sometimes a bit hard to read, but ok. And the Jedec files for the main GAL, as well as the data to create this GAL. (20V8) And the Jedec file for the SMTP-Gal, a 16V8 So in my opinion, enough to recreate a Midex+ expander. Just let me know an E-M...
by guus.assmann
Sat Jan 20, 2018 10:46 am
Forum: Hardware
Topic: Upgrading serial port for higher speed / more midi stability
Replies: 121
Views: 19608

Re: Upgrading serial port for higher speed / more midi stability

Hello, Would a Steinberg Midex+ interface do the right job? As it happens, I do have a lot of data on that. There's the schematic diagrams, GAL files and data for the modification. (Originally the Midex has PAL's) And there's a document for a Falcon mod. (That I've not tried yet) Also, I have test p...
by guus.assmann
Thu Dec 14, 2017 8:42 pm
Forum: Hardware
Topic: PAK68/3 and FRAK/2 schematic
Replies: 19
Views: 7012

Re: PAK68/3 and FRAK/2 schematic

Hello Artik-wroc,
Have a look at the cabling for the power supply.
Specially the minus needs to be very big, large surface.
Memory creates spikes in supply voltages.
BR/
Guus
by guus.assmann
Thu Dec 14, 2017 8:40 pm
Forum: Hardware
Topic: PAK68/3 and FRAK/2 schematic
Replies: 19
Views: 7012

Re: PAK68/3 and FRAK/2 schematic

Hello Olverg,
It is possible to use FPU or CPU at lower speed. Also at different speed.
Like CPU @ 33Mhz and FPU @50Mhz or even 66Mhz, overcolcing a FPU is often no problem.
And the 68000 family is A-Syncronus, so no problem.
BR/
Guus
by guus.assmann
Sat Sep 30, 2017 7:11 pm
Forum: Hardware
Topic: Pardon me for asking...
Replies: 3
Views: 1256

Re: Pardon me for asking...

Hello clh333, Normally, removing all the screws that are in a "square hole" will enable you to take an Atari computer apart. For the Mega ST, lift the back as far as you can and try to slide the plastic to the front. This will enable you to move it past the front of the floppy drive. It he...
by guus.assmann
Thu Aug 24, 2017 12:34 pm
Forum: Hardware
Topic: Yet another dumb ST to VGA adaptor, take 2
Replies: 9
Views: 2673

Re: Yet another dumb ST to VGA adaptor, take 2

Really nice.
I want to buy one.
For some reason the PM's I write are still in the outbox and apear bot to be sent.
Can you please try to contact me?
Thanks.
by guus.assmann
Sat Feb 18, 2017 5:09 pm
Forum: Hardware
Topic: Need help with PAK 68/2
Replies: 28
Views: 5253

Need help with PAK 68/2

It may help to replace the 74LS244 and 74LS373 by a couple of F-types.
This makes the access to Ram a bit faster and often more reliable.

The PAK always needs the ROM's in the MB to start.
It uses the reset vector in these.

BR/
Guus
by guus.assmann
Fri Sep 02, 2016 4:02 pm
Forum: Hardware
Topic: Booster 020 by Jean Conter
Replies: 22
Views: 5827

Booster 020 by Jean Conter

My 4 CPU's:
68020RC16B 2A70N8633
68020RC12B 2A70N8747
These 2 work fine in the booster20

68020RC16B 2A70N8807
68020RC12B 2A70N8633
Don't work in the Booster20 but are ok in the Pak68/2
BR/
Guus
by guus.assmann
Thu Sep 01, 2016 7:40 pm
Forum: Hardware
Topic: Booster 020 by Jean Conter
Replies: 22
Views: 5827

Re: Booster 020 by Jean Conter

The Booster020 works fine with a blitter. I have two 020's and tested in 5 individual MegaST boards. These are of various revisions, 1MB, 2MB, 4MB with different chips. Also with IMP chips. Maybe the combination with 16Mhz is not ok for the blitter? And not all CPU's work fine. Out of 6, I only had ...
by guus.assmann
Wed Aug 17, 2016 8:57 pm
Forum: Hardware
Topic: PPera/Popsel IDE interface Gal speed
Replies: 1
Views: 1068

PPera/Popsel IDE interface Gal speed

The PCB's are ready, I just need to program and mount the Gal's.
What speed is needed for these?
I have 16V8 in 25nS, 15 nS and 7nS.
Can I use the 25nS ones or do they need to be faster.

BR/
Guus
by guus.assmann
Mon Aug 15, 2016 8:21 am
Forum: Hardware
Topic: Atari TT Real time clock precision
Replies: 3
Views: 1210

Re: Atari TT Real time clock precision

Hello Guilaume, Just now, I've checked the schematics for the TT. It uses the MC146818 clock chip. And an external clock generator, using a 4069 chip, U402. Only 2 gates A and B are used. Using this C-Mos chip gives a lower power consumption than having the MC146818 do the oscillator. (It can) The c...
by guus.assmann
Mon Aug 15, 2016 7:56 am
Forum: Hardware
Topic: Atari TT Real time clock precision
Replies: 3
Views: 1210

Re: Atari TT Real time clock precision

It may very well be that it can be adjusted. On the much older MegaST, there's an adjustable capacitor. And the same on a MegaSTE. For these 2, I have a bare board and had a look. For the TT, I'm not sure. But it can very well be the case. (Check the schematics) If you can't find it, let me know and...
by guus.assmann
Fri Aug 05, 2016 4:39 pm
Forum: Hardware
Topic: PAK68/2 PCB Project ...
Replies: 109
Views: 68775

PAK68/2 PCB Project ...

Today I put a socket in a MegaST 2.
For the rest it's standard and has the IMP Shifter, MMU, Glue and DMA.
I've left the Tos 1.04 in it.
The PAK68/2 works just fine. I've tested with Gembench 6 and 4.03
That's 3 different boards they do work in. (I have 2 peices)
BR/
by guus.assmann
Wed Aug 03, 2016 7:38 pm
Forum: Hardware
Topic: Mega ST4 CPU stuck in HALT Condition
Replies: 31
Views: 6959

Re: Mega ST4 CPU stuck in HALT Condition

My diagnostics card is most likely the same. But it you also have some short between data lines, I guess it may go wrong. Or there's been another failure on my MB. I know that I only fixed the memory to get it working again. But I had the good luck of starting out with a MegaST 1 that was working be...

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