Search found 7355 matches

by hoglet
Sun Feb 02, 2014 6:25 pm
Forum: other vintage computer hardware, software and games
Topic: Upgrading an Atari 520 STFM's Memory
Replies: 28
Views: 6804

Re: Upgrading an Atari 520 STFM's Memory

:( :( :( :( :( I've just tried the following configs, and neither worked: - Bank 0 (disabled) Bank 1 (2MB) - Bank 0 (2MB) Bank 1 (disabled) So, I'm starting to think that in addition to a problematic MCU, my 2MB RAM bank may also have some compatibility issues. The one thing I don't really understan...
by hoglet
Sun Feb 02, 2014 5:19 pm
Forum: other vintage computer hardware, software and games
Topic: Upgrading an Atari 520 STFM's Memory
Replies: 28
Views: 6804

Re: Upgrading an Atari 520 STFM's Memory

Mark just emailed me the instructions for his XTRA-Ram board. On pages 8 it states: ...Since Atari ST's containing 100109 type MMU chips can only use memory banks of the same capacity.... In the appendix it states: ...ALL existing memory needs turning OFF if you have a 100109 type MMU chip and are a...
by hoglet
Sun Feb 02, 2014 4:11 pm
Forum: software: new games
Topic: Atomic Joe Blade
Replies: 22
Views: 2931

Re: Atomic Joe Blade

Hi Kees,

I was wonder what you were up to as you have been so quiet recently. :lol: :lol: :lol: :lol:

Dave
by hoglet
Sun Feb 02, 2014 4:00 pm
Forum: other vintage computer hardware, software and games
Topic: Upgrading an Atari 520 STFM's Memory
Replies: 28
Views: 6804

Re: Upgrading an Atari 520 STFM's Memory

Thanks for your help so far Mark, much appreciated. I'm starting to think that I might be hitting MCU issues. It seems there are several MCU implementations, and some of these have compatibility issues with 2.5MB configurations. I've also read reports that 2.5MB does work, but only with the 2MB in b...
by hoglet
Sun Feb 02, 2014 2:52 pm
Forum: other vintage computer hardware, software and games
Topic: Upgrading an Atari 520 STFM's Memory
Replies: 28
Views: 6804

Re: Upgrading an Atari 520 STFM's Memory

And another data point, I've just noticed that bank 1 is now showing up as 2048KB in Sys Info and the MMC config register is set to 06 (00000110) which is consistent with this. This does seem to imply that bank 1 has passed the memory test in the BIOS that sizes the RAM. which involves writing a seq...
by hoglet
Sun Feb 02, 2014 12:55 pm
Forum: other vintage computer hardware, software and games
Topic: Upgrading an Atari 520 STFM's Memory
Replies: 28
Views: 6804

Re: Upgrading an Atari 520 STFM's Memory

OK, here's another data point. The Bank1 CAS0 and CAS1 signals are always high, even when I press and release RESET. The scope never triggers, and it should trigger of a singe negative edge. I've traced the signals back to the MMU, and it's the same on the MMU. I have another older ST motherboard, w...
by hoglet
Sun Feb 02, 2014 11:32 am
Forum: other vintage computer hardware, software and games
Topic: Upgrading an Atari 520 STFM's Memory
Replies: 28
Views: 6804

Re: Upgrading an Atari 520 STFM's Memory

OK, the is getting weirder.... I've written a tiny GFA Basic program: a=&H80000 SDPOKE a,&HAAAA FOR i=0 TO 100 x=DPEEK(a) PRINT HEX$(x) NEXT i When I run this with a=&H70000 it works as expected When I run this with a=&H80000 I get randomly changing data (usually either 4 or FFFF, but sometimes othe...
by hoglet
Sun Feb 02, 2014 7:58 am
Forum: other vintage computer hardware, software and games
Topic: Upgrading an Atari 520 STFM's Memory
Replies: 28
Views: 6804

Re: Upgrading an Atari 520 STFM's Memory

Hi Mark, Thanks for memory test programs. I've just given them a try, and the problem is that they only test the amount of memory that TOS thinks is there. That seems to be 512KB in my case, so it does look like the additional MT4C4001 RAM I've added is not working properly yet. If this were a Beeb,...
by hoglet
Sat Feb 01, 2014 11:16 pm
Forum: other vintage computer hardware, software and games
Topic: Upgrading an Atari 520 STFM's Memory
Replies: 28
Views: 6804

Re: Upgrading an Atari 520 STFM's Memory

jonb wrote:You're not using HDDRIVER are you?
I have no idea! :lol:

Anyway, I've now got it working. All I needed to do was to boot straight from the Elite disk. It's amazing what you forget in 25 years!

Tomorrow I'll try to get a RAM TEST program working.

Dave
by hoglet
Sat Feb 01, 2014 8:35 pm
Forum: other vintage computer hardware, software and games
Topic: Upgrading an Atari 520 STFM's Memory
Replies: 28
Views: 6804

Re: Upgrading an Atari 520 STFM's Memory

Hi Mark, Thanks for all the info. There are 6 ROM sockets, and 2 ROMs: - C101631-002 - C101632-002 The nearest I can find on the interweb was: C101631-001 = TOS 1.02 2Chip QWERTY High C101632-001 = TOS 1.02 2Chip QWERTY Low I went ahead and unsoldered the 1Mx4 chips from the SIMMs, and fitted 4 of t...
by hoglet
Sat Feb 01, 2014 6:09 pm
Forum: acorn atom
Topic: Atom repair progress
Replies: 136
Views: 10544

Re: Atom repair progress

Jms2, Out of interest, were you measuring with a meter or the scope? Pin 9 of the 6847 is an internally generated voltage reference (CB - Chroma Bias) and this should be 1.5V DC. If you are sure you have good GND (pin 1) and 5V (pin 17) connections, then if you are not getting 1.5V on pin 9 the the ...
by hoglet
Sat Feb 01, 2014 5:23 pm
Forum: other vintage computer hardware, software and games
Topic: Upgrading an Atari 520 STFM's Memory
Replies: 28
Views: 6804

Upgrading an Atari 520 STFM's Memory

Hi all, I'm sure there are some very knowledgeable Atari folk on here, like Mark (1024MAK). I'm after a bit of advice... Last year at a boot sale I picked up an old Atari 520 STFM. Here are some details: - Motherboard C103414-001 Rev 11 - Memory 512KB - Memory organization 4x 256Kx4 Fast Page Mode D...
by hoglet
Sat Feb 01, 2014 10:09 am
Forum: acorn atom
Topic: Atom GODIL VGA Adapter
Replies: 414
Views: 34489

Re: Atom GODIL VGA Adapter

Roland, A version register is a great suggestion. Once I've added the hardware scrolling windows registers, I'm happy to declare a version 1. I'll also merge the vga80 branch in git back into master. I was also wondering whether we should move some of the registers around in the 9Fxx mode, so that t...
by hoglet
Thu Jan 30, 2014 9:12 pm
Forum: acorn atom
Topic: Atom repair progress
Replies: 136
Views: 10544

Re: Atom repair progress

You've got a pretty decent scope, a Rigol?

Any chance of posting some screen shots of the composite video output (PL4 pin 9)?

What have you tried connecting this to?

Dave
by hoglet
Thu Jan 30, 2014 9:02 pm
Forum: acorn atom
Topic: Atom repair progress
Replies: 136
Views: 10544

Re: Atom repair progress

I really don't see how the lack of a battery would cause the write signal to be blocked, but measuring the voltage on pin 1 of the 4075 would confirm one way or the other (it should be close to 0v, not 4v) This card has worked for you in the past without a battery, correct? It's a bit strange this o...
by hoglet
Thu Jan 30, 2014 7:51 am
Forum: acorn atom
Topic: Atom repair progress
Replies: 136
Views: 10544

Re: Atom repair progress

jms2 wrote:I wonder if my incorrect dc supply arrangement could have fried something?
I think it would only fry something on the Atom if you actually reversed the power supply lines, or if the power supply voltage significantly exceeded 5V.

Is this possible?

Dave
by hoglet
Wed Jan 29, 2014 10:59 pm
Forum: software
Topic: !ADFFS
Replies: 73
Views: 13196

Re: !ADFFS

There are some VGA monitors that will sync to a vertical frequency of 50Hz, as long as the horizontal frequency is greater than 30KHz. For example, The HP LP2065 which I use does: Horizontal frequency: 30-94 kHz (VGA), 30-92 kHz (DVI), Vertical frequency: 48-85 Hz (VGA), 30-92 kHz (DVI) linky Dave
by hoglet
Wed Jan 29, 2014 10:25 pm
Forum: for sale / freebies
Topic: Needham EMP-20 Device Programmer
Replies: 17
Views: 2124

Re: Needham EMP-20 Device Programmer

Hi Dave,

I'd be interested in one of them.

The device list looks better than the G540 (which has already failed to program a couple of devices it claims to support), and it seems to have an excellent reputation as being a decent programmer.

Dave
by hoglet
Wed Jan 29, 2014 7:21 am
Forum: acorn atom
Topic: Atom GODIL VGA Adapter
Replies: 414
Views: 34489

Re: Atom GODIL VGA Adapter

Hi Roland,

Thanks for your input, I think I agree, and I'll leave the 80 column mode.

I might have a go at the scroll window registers for the Atom modes at the weekend.

Dave
by hoglet
Mon Jan 27, 2014 10:33 pm
Forum: wanted
Topic: A5000 keyboard/mouse + ARM Arch Ref Manual
Replies: 34
Views: 2297

Re: A5000 keyboard/mouse + ARM Arch Ref Manual

IanB designed a nice little PIC based adapter that allows you to connect a normal PS/2 mouse and keyboard. I made one last year. Here's the thread with some details, but you'll probably want to talk to Ian if you go down this path: http://www.stardot.org.uk/forums/viewtopic.php?f=16&t=6789 There are...
by hoglet
Mon Jan 27, 2014 8:21 pm
Forum: acorn atom
Topic: Atom GODIL VGA Adapter
Replies: 414
Views: 34489

Re: Atom GODIL VGA Adapter

More goodies? Is it possible to scroll only a part of the screen? In a game like Repton there's only a part of the screen scrolling. I really haven't any idea how this can be done with normal logic but I was simply wondering... I think in principle this should be possible, at least for the original...
by hoglet
Sun Jan 26, 2014 8:56 pm
Forum: acorn atom
Topic: Atom repair progress
Replies: 136
Views: 10544

Re: Atom repair progress

It is only 4.2V at the 43256 ram chip on the Combikaart, and on a couple of nearby logic chips. I don't know why this is occurring, but as it is very localised I doubt it is a problem. On the Combikaart I think there is a silicon diode in series with the power to the RAM and a couple of the CMOS lo...
by hoglet
Sun Jan 26, 2014 5:19 pm
Forum: acorn atom
Topic: Atom GODIL VGA Adapter
Replies: 414
Views: 34489

Re: Atom GODIL VGA Adapter

Last update for today.... I managed to fix the horizontal scrolling in the vga80x40 mode so that it works exactly the same as in the native Atom modes, i.e. a line wraps onto itself, rather onto the previous line. I didn't think this was going to be possible, but then I realized that MOD 80 can be d...
by hoglet
Sun Jan 26, 2014 1:49 pm
Forum: acorn atom
Topic: Atom GODIL VGA Adapter
Replies: 414
Views: 34489

Re: Atom GODIL VGA Adapter

Roland, I've got hardware scrolling working in the VGA80x40 mode now. This is the VHDL I ended up with: process (scroll_h, scroll_v, vga80_addrb) variable display_start : std_logic_vector(11 downto 0); variable addr : std_logic_vector(13 downto 0); begin -- calculate the display start as 80 * scroll...
by hoglet
Sun Jan 26, 2014 9:21 am
Forum: acorn atom
Topic: Atom repair progress
Replies: 136
Views: 10544

Re: Atom repair progress

There are three 6847P's on ebay at the moment.
http://www.ebay.co.uk/sch/i.html?_nkw=mc6847p
Going rate seems to be £7.50

Dave
by hoglet
Sun Jan 26, 2014 9:17 am
Forum: acorn atom
Topic: Atom GODIL VGA Adapter
Replies: 414
Views: 34489

Re: Atom GODIL VGA Adapter

I think this logic might work for the vga80x40 mode. -- calculate the new screen start address, extending the precision by one bit addr := ('0' & vga80_addrb) + ('0' & display_start); -- detect wrapping in wrapping in the character and attributevregions if ((vga80_addrb < 3200 and addr >= 3200) or a...
by hoglet
Sun Jan 26, 2014 8:37 am
Forum: acorn atom
Topic: Atom GODIL VGA Adapter
Replies: 414
Views: 34489

Re: Atom GODIL VGA Adapter

Roland, At the moment the hardware scrolling works just for the original Atom modes. The reason I didn't immediately add it for the 80x40 mode is that the scheme Kees invented, that allows independent scrolling in the H and V dimension, with perfect wrap around, relies on the screen width being a po...
by hoglet
Sat Jan 25, 2014 9:14 pm
Forum: acorn atom
Topic: Atom GODIL VGA Adapter
Replies: 414
Views: 34489

Re: Atom GODIL VGA Adapter

Hi Guys, I've just added hardware scrolling to the GODIL. It's implemented rather like the article in Atom Nieuws 18 years ago by Kees: http://atomclub.nl/atom_nieuws/1996/nr2/19962007.htm Scrolling is possible independently in the X and Y dimensions. It should work with all the standard Atom screen...
by hoglet
Sat Jan 25, 2014 9:40 am
Forum: acorn atom
Topic: Atom repair progress
Replies: 136
Views: 10544

Re: Atom repair progress

Hi Jms2,

Even if there are no video RAMs present, I believe you should get a stable display from the 6847, with each character the same (probably an @ character).

Dave