Thanks Mike, i'll have a look at it tonight when the kids are asleep.Mike wrote:I was forewarned by your post in Forum64.moggep wrote:Threadlift of the Century!
Please take a look at the first program, EASYDUMP, in this thread.[...] my major question is about the ROM that is installed. It has a handwritten sticker that says "Screen ROM". Anyone knows what it is, and how to activate it?
The EPROM should be located in BLK5, but may not always be visible, depending on how the DIP-switches (especially 1 and 4) are set. The program stores a memory dump (5 corresponds to the range $A000..$BFFF, where most cartridge ROMs are located) on floppy, or SD-card with a SD2IEC, etc.
If you can provide the ROM image I will take a look at the code.
How do you use a multi-slot expander (motherboard)?
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Re: How do you use a multi-slot expander (motherboard)?
Re: How do you use a multi-slot expander (motherboard)?
Thanks for a great program.
Attached are the dump-files. There are three files in the archive, with different switch settings.
blk5-00a000 Dipswitch 1 off and 4 off
blk5-01a000 Dipswitch 1 off and 4 on
blk5-11a000 Dipswitch 1 on and 4 on
Hope you can get something out of it.
Attached are the dump-files. There are three files in the archive, with different switch settings.
blk5-00a000 Dipswitch 1 off and 4 off
blk5-01a000 Dipswitch 1 off and 4 on
blk5-11a000 Dipswitch 1 on and 4 on
Hope you can get something out of it.
- Attachments
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- dumps.rar
- (21.14 KiB) Downloaded 49 times
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Re: How do you use a multi-slot expander (motherboard)?
I plugged 5 VICs to one RAM cartridge once.
It didn't work.
It didn't work.
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Re: How do you use a multi-slot expander (motherboard)?
@moggep
What you have there is a very interesting cartridge. Instead of using multiple 8k x 8 SRAM chips or perhaps a single 32k x 8 SRAM chip, it uses 4 DRAM chips of 16k x 4.
This means it has a built-in system for multiplexing the addresses and a refresh system.
I have a schematic for doing something like that here but I have never tested it and I suspect it may be incomplete.
What you have there is a very interesting cartridge. Instead of using multiple 8k x 8 SRAM chips or perhaps a single 32k x 8 SRAM chip, it uses 4 DRAM chips of 16k x 4.
This means it has a built-in system for multiplexing the addresses and a refresh system.
I have a schematic for doing something like that here but I have never tested it and I suspect it may be incomplete.
Be normal.
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Re: How do you use a multi-slot expander (motherboard)?
To my surprise, the files came out with a size of about 47K. Actually they were supposed to be 8K in size.moggep wrote:Attached are the dump-files. There are three files in the archive, with different switch settings.
You made a typo in line 22 of the program: POKE194,S uses the letter "S", not the digit "5". This made the program dump the whole memory from $0500 to $BFFF (including EASYDUMP itself) and thus I could infer what went wrong.
Unfortunately none of these 3 combinations turned up with recognisable ROM code in what the files saved from $A000 to $BFFF. However, the combinations 01 and 11 seem to map RAM into BLK5.blk5-00a000 Dipswitch 1 off and 4 off
blk5-01a000 Dipswitch 1 off and 4 on
blk5-11a000 Dipswitch 1 on and 4 on
The combination 10 is missing. Maybe this one maps in the ROM.
If possible, please use *.zip instead of *.rar to produce the archive.
Re: How do you use a multi-slot expander (motherboard)?
Of course i did, it's obvious when you say it.Mike wrote: To my surprise, the files came out with a size of about 47K. Actually they were supposed to be 8K in size.
You made a typo in line 22 of the program: POKE194,S uses the letter "S", not the digit "5". This made the program dump the whole memory from $0500 to $BFFF (including EASYDUMP itself) and thus I could infer what went wrong.
I'll give it another try tonight, with 4 files this time. Thanks for your effort.blk5-00a000 Dipswitch 1 off and 4 off
blk5-01a000 Dipswitch 1 off and 4 on
blk5-11a000 Dipswitch 1 on and 4 on
Unfortunately none of these 3 combinations turned up with recognisable ROM code in what the files saved from $A000 to $BFFF. However, the combinations 01 and 11 seem to map RAM into BLK5.
The combination 10 is missing. Maybe this one maps in the ROM.
If possible, please use *.zip instead of *.rar to produce the archive.
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Re: How do you use a multi-slot expander (motherboard)?
If you just supply the missing combination (1 ON and 4 OFF), that is entirely sufficient.I'll give it another try tonight, with 4 files this time.
As I wrote, the first three files already contained a dump of the address range in question (BLK5), even if some more of the memory was saved alongside it.
Re: How do you use a multi-slot expander (motherboard)?
Here's the missing piece. You were totally right, i made a typo in line 22.Mike wrote:If you just supply the missing combination (1 ON and 4 OFF), that is entirely sufficient.I'll give it another try tonight, with 4 files this time.
As I wrote, the first three files already contained a dump of the address range in question (BLK5), even if some more of the memory was saved alongside it.
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- blk5-10a000.zip
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Re: How do you use a multi-slot expander (motherboard)?
And Bingo!moggep wrote:Here's the missing piece. [...]
A quick peek reveals a toolkit that is mapped into BLK5. The EPROM is only 4K in size, and so the original appears at $A000..$AFFF and is then mirrored to $B000..$BFFF.
SYS 40960 outputs some status/debug info of current BASIC RAM limits, position of screen RAM, and VIC register settings.
I will have to investigate further: this ROM possibly provides a BASIC editor capable of handling another number of columns and rows than the standard 22x23 layout.
Re: How do you use a multi-slot expander (motherboard)?
Nice! And it would be even nicer if it is such BASIC editor.Mike wrote:And Bingo!moggep wrote:Here's the missing piece. [...]
A quick peek reveals a toolkit that is mapped into BLK5. The EPROM is only 4K in size, and so the original appears at $A000..$AFFF and is then mirrored to $B000..$BFFF.
SYS 40960 outputs some status/debug info of current BASIC RAM limits, position of screen RAM, and VIC register settings.
I will have to investigate further: this ROM possibly provides a BASIC editor capable of handling another number of columns and rows than the standard 22x23 layout.
I noticed a difference in the output if i try sys40960 two times in a row. After the 1st run it seems to occupy some of the RAM. (see pics)