memory maker 64k

[Mike]

I found something at $A800. So I saved $A800-$AFFF from VICMON. You can download it here: http://dl.dropbox.com/u/9954627/64KEXPANSION.PRG
I hope nothing did go wrong on copying it from VIC-20 to Amiga 4000 to Windows7 to Dropbox.

That's the program on EPROM.

It is just missing one byte at the end, which in this case is no problem since the last few bytes are fill bytes ($FF). For many monitor programs the end address given on save is exclusive, just so you know.

From a quick look I found there is a memory test routine inside, and kernal vectors are being hooked. Will investigate further ...

Edit: seems you already found the mem test at $AD00 as well.

[leof]

Edit: seems you already found the mem test at $AD00 as well.

Yes, and it runs OK.
I'm now peeking at the memory blocks with different dipswitch settings more systematically. I will post the results.

[Mike]

I've found hints that the software could actually be similar to (or even the same as) another 64K card by ROOS Electronik.

You could try SYS43008, with the range $0400 .. $0FFF enabled (this range is used to hold status information):

After this, eight new 'devices' with the numbers 200 .. 207 are available, each of them is capable to hold one file. These files can be accessed with SAVE, LOAD, OPEN, PRINT#, GET#, INPUT#, and CLOSE.

Does this work?

[leof]

You could try SYS43008, with the range $0400 .. $0FFF enabled (this range is used to hold status information):

After this, eight new 'devices' with the numbers 200 .. 207 are available, each of them is capable to hold one file. These files can be accessed with SAVE, LOAD, OPEN, PRINT#, GET#, INPUT#, and CLOSE.

Does this work?

Yes, this works.

[tokra]

Ok, now it's getting interesting. As mentioned I have the MemoryMaker 64K as well. I just did the same and switched DIP 1 to off and then dumped $a800-$afff to a file:

http://www.tokra.de/vic/memmaker64k.prg

As Mike suggested I can type SYS43008 and the use SAVE, LOAD, ... with devices 200 to 207 - what this saves I'm not sure. I would assume each area is one 8K block.

I assume Mike has the info on the ROOS Elektronik 64K card from 64er-magazine 9/1984. I've checked this as well and there's and advert from ROOS Elektronik in this issue on page 131. Down at the bottom of this advert they have some sort of company logo which looks a little like a slashed 0. In fact the comany name is ROOS/ZERO and had offices in the Netherlands, England and Sweden back then as well. The german office was close to the Dutch border, which makes me think this was a dutch company to begin with.

Also on http://vic20.de/html/64k_karten.html you can see the slashed zero logo on the cart as well. So I'm pretty sure this in fact IS the Roos Elektronik expansion.

I also noted I can type SYS44288 ($ad00) and get some menu of which one option is a RAMTEST. The menu says "KIES" at the bottom which according to GoogleTranslate means "choose" in dutch - one more hint this was a dutch company. I cannot figure out what the other menu-options do.

leof's image can do the SYS44288 as well but goes straight to RAMTEST, which makes me think the one I have is a different version.

Maybe we can reverse engineer this one even further

[leof]

As Mike suggested I can type SYS43008 and the use SAVE, LOAD, ... with devices 200 to 207 - what this saves I'm not sure. I would assume each area is one 8K block.

It saves a BASIC program. Make a one-line program (e.g. 10 PRINT "TEST") and save it. Type NEW and LOAD it again from the "device" you saved it to. But I'm sure you can save other data as well. It's not clear however how many data it can hold.

I assume Mike has the info on the ROOS Elektronik 64K card from 64er-magazine 9/1984. I've checked this as well and there's and advert from ROOS Elektronik in this issue on page 131. Down at the bottom of this advert they have some sort of company logo which looks a little like a slashed 0. In fact the comany name is ROOS/ZERO and had offices in the Netherlands, England and Sweden back then as well. The german office was close to the Dutch border, which makes me think this was a dutch company to begin with.

Do you have a scan from this page from 64er-magazine 9/1984?

I also noted I can type SYS44288 ($ad00) and get some menu of which one option is a RAMTEST. The menu says "KIES" at the bottom which according to GoogleTranslate means "choose" in dutch - one more hint this was a dutch company.

As I am Dutch I can confirm you are right. What other options can you choose from?

Maybe we can reverse engineer this one even further

That's what I'm after!

[tokra]

Do you have a scan from this page from 64er-magazine 9/1984?

Not at hand, and there's really no more info there than already mentioned here.

As I am Dutch I can confirm you are right. What other options can you choose from?

You can try yourself. Just load my ROM-dump into VICE and type SYS44288.

[leof]

You can try yourself. Just load my ROM-dump into VICE and type SYS44288.

Where can I find the ROM dump?

[tokra]

Read my post from "Fri Feb 17, 2012 11:08 pm" - it's linked right there!

[leof]

Read my post from "Fri Feb 17, 2012 11:08 pm" - it's linked right there!

Sorry Tokra, overlooked that one!
Tried it and seems to be unfinished.

[leof]

In fact the comany name is ROOS/ZERO and had offices in the Netherlands, England and Sweden back then as well. The german office was close to the Dutch border, which makes me think this was a dutch company to begin with.

There still is a Roos Electronics in Holland but it's not near the German border: http://www.actiever.nl/bedrijf/81/gilze ... cs-bv.html. So I thinks it's not the same company.

I now checked all 64 possible dipswitch combinations. Some of them don't work (no display) and with four of them I get the Ramtest program. I haven't yet peeked in RAM in all situations as I have the VICMON that installs at $6000. But I do not expect to find more logic in the EPROM as we have found up till now.
Furthermore I fear for connector problems on the VIC because of the many times of installing and removing the expansion as I don't have a multiple user port extension.

[tokra]

I recently found the german manual for the Memory Maker 64K on the german Forum64.de. Must have missed this back in February 2012, mere 4 days after the last post on this topic... Anyhow, here are the 3 pages





The german in the manual is pretty bad, obviously this was a translation.

Basically DIP-switches 4, 5 and 6 control the areas $6000-$7fff, $4000-$5fff and $2000-$3fff

Switch 2 controls the area from $a000-$bfff. Switches 1 and 3 then control RAM or EPROM.

Switch 1 set to "off" seems to activate the 2K-EPROM at $a800 and switch 3 also maps this to $a000 as well. It is then visible at both $a000 and $a800 - whatever this might be good for I don't know. In my experiments I wasn't able to have the EPROM show ONLY at $a000.

The manual warns however that if Switch 2 is set to off, Switch 1 must be set to On (=RAM). No idea why though.

Further the manual says that when area $a000-$afff is set to RAM it will share the same information with $0400-$0fff. I suppose they meant $a400-$afff however, since it would make no sense otherwise. This also means that it is not possible to deactivate RAM at $0400-$0fff separately, which makes it impossible to do a 35K-expansion with the device, even with a slot-expander. The manual specifically warns about using memory expansions, specifically the VIC-1210 (3K RAM expansion).

At the very end the manual mentions how the memory on the board can be switched in two 32K-blocks. This is done by writing 0 or 128 to $9bff (39935). Default after power-on is 0. So basically you can flip the whole expansion memory just like with the Final Expansion.

[leof]

Good find! Thanks!

[mrr19121970]

Someone is selling one on forum64.de for 15 euros posted

[dragos]

link please