Micro-KIM EPROM expansion?

Talk about your Micro-KIM

Micro-KIM EPROM expansion?

Postby Paul Förster » May Fri 02, 2014 7:35 am

Hi,

6 KB of the 8 KB EPROM is unused as the (Micro-) KIM has only a 2 KB ROM. I wonder if it is possible to either map the remaining 6 KB somewhere into the available address space (possibly behind 0xa000 to not have a conflict with the 32 KB expansion board) or is there an EPROM expansion board available? The latter would allow another 24 KB of address space. It would be really cool because that'd allow porting the C64 kernel and BASIC to the KIM. All that would be needed is to remove all C64 graphics and I/O stuff and redirect CHRIN and CHROUT to the KIM ROM as well as remapping a few zero-page locations.

This way, you can have Commodore (Microsoft) BASIC V2 in ROM available at power up. And if the ROM space would be 24 KB instead of 16 KB needed for the C64 port of kernel and BASIC, there could also be a real machine language monitor too. How's that for an idea. But to do that, I'd need at least 16 KB ROM space, 24 would be better.

Vince, is there something like an EPROM expansion card that maps to 0xa000-0xffff in your queue? That'd be a REALLY cool project, don't you think? Or could a second memory expansion board with the RAM chip replaced by an EPROM and relocated to 0xa000 instead of 0x2000 do the job?

Cheers,

Paul
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Re: Micro-KIM EPROM expansion?

Postby cappy2112 » Jan Wed 21, 2015 5:29 pm

I'm curious- as to how having Commodore basic would be useful, since none of the Commodore hardware would be present to take advantage of.
Why not at Tiny Basic or one of the generic Basics, that are not tied to specific hardware?
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Re: Micro-KIM EPROM expansion?

Postby djones60 » Jan Thu 22, 2015 10:06 am

I'd go with the tiny basic. Or compile the basic for an OSI superboard, since it's pretty generic. That OSI would just need changes for made keyboard/screen character I/O.
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Re: Micro-KIM EPROM expansion?

Postby Paul Förster » Feb Sun 01, 2015 4:23 am

Hi Cappy2112,

sorry for the late answer. I'm not exactly here often. :-)

There's nothing special about Commodore BASIC. My idea was just to remove cassette routines and routines that deal with the Commodore serial I/O, the SID, VIC, etc., thus making the ROM smaller. But I'd leave (and modify) the screen handling routines in so that one could have full screen editing on a standard serial terminal (e.g. VT100 or VT220). I just think that is probably the easiest way to get a BASIC with full screen handling. That was my idea. I don't know if it would even be feasible. My dream was just to get a BASIC with full screen editing capabilities and not just a line oriented one.

Still, (EP)ROM space, i.e. an EPROM card would be great to have as it would allow burning other stuff into an EPROM and just plugging it in too, not only BASIC. I would even more appreciate it if such a card could hold more than one EPROM which could be put at different addresses and/or be enabled or disabled individually.

Cheers,

Paul
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Re: Micro-KIM EPROM expansion?

Postby jac_goudsmit » Feb Mon 02, 2015 4:35 pm

Paul Förster wrote:There's nothing special about Commodore BASIC. My idea was just to remove cassette routines and routines that deal with the Commodore serial I/O, the SID, VIC, etc., thus making the ROM smaller. But I'd leave (and modify) the screen handling routines in so that one could have full screen editing on a standard serial terminal (e.g. VT100 or VT220). I just think that is probably the easiest way to get a BASIC with full screen handling. That was my idea. I don't know if it would even be feasible. My dream was just to get a BASIC with full screen editing capabilities and not just a line oriented one.


The screen editor on Commodore computers is one of my favorites; I think the IBM PC basic / basica had a screen editor that basically functioned the same: The cursor keys will take you anywhere on the screen and when you hit enter, the editor figures out which physical lines belong to the logical line at the cursor position and sends the entire logical line to the BASIC interpreter. The editor is not part of the BASIC ROM. Neither are the routines to handle disk and tape, and as far as I know there aren't any ROM routines to control the VIC, SID etc. -- the programmer was expected to do this her/himself. Things like LOAD and SAVE are provided by the Kernal (in Commodore-speak) and commands like DLOAD, DIRECTORY etc. were also implemented in the Kernal as BASIC extensions. The BASIC ROM on Commodore is not that different from other early 6502 BASICs by Microsoft such as OSI or KIM. I've never looked into it, but It wouldn't surprise me if it's trivial to build a ROMable version of KIM-1 BASIC from the sources on pagetable.com, so it's not even necessary to change a lot of code. But to get the screen editor, you'll have to modify the Commodore editor ROMs which is probably going to be a lot of work.

Still, (EP)ROM space, i.e. an EPROM card would be great to have as it would allow burning other stuff into an EPROM and just plugging it in too, not only BASIC. I would even more appreciate it if such a card could hold more than one EPROM which could be put at different addresses and/or be enabled or disabled individually.


It would be even better to have an EEPROM such as the 28C256 (32KB, less than $8) so you don't need an EPROM burner or UV eraser; the 6502 on the MicroKim will be able to write data to it as if it's a RAM chip. If the hardware design is done in a smart way, it will be possible for the 6502 to copy data from the motherboard EPROM to the expansion EEPROM.

I've been playing with a couple of ideas like that in my head for a while, but there are many other things that demand my attention. However I just put an order in to Mouser for replacements of my MicroKim RAM chips which have been broken for a long time. Maybe I'll get to it soon.

===Jac
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Re: Micro-KIM EPROM expansion?

Postby cappy2112 » Feb Sun 08, 2015 12:20 am

jac_goudsmit wrote:
It would be even better to have an EEPROM such as the 28C256 (32KB, less than $8) so you don't need an EPROM burner or UV eraser; the 6502 on the MicroKim will be able to write data to it as if it's a RAM chip. If the hardware design is done in a smart way, it will be possible for the 6502 to copy data from the motherboard EPROM to the expansion EEPROM.

I've been playing with a couple of ideas like that in my head for a while, but there are many other things that demand my attention. However I just put an order in to Mouser for replacements of my MicroKim RAM chips which have been broken for a long time. Maybe I'll get to it soon.

===Jac


This sounds interesting Jac, do keep us posted.
I'll be building the Microkim within a few weeks, as soon as I finish a previous project.

BTW- is there a monitor in the Microkim?
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Re: Micro-KIM EPROM expansion?

Postby cappy2112 » Feb Sun 08, 2015 12:29 am

Paul Förster wrote:Hi Cappy2112,

e.g. VT100 or VT220). I just think that is probably the easiest way to get a BASIC with full screen handling. That was my idea. I don't know if it would even be feasible. My dream was just to get a BASIC with full screen editing capabilities and not just a line oriented one.

Still, (EP)ROM space, i.e. an EPROM card would be great to have as it would allow burning other stuff into an EPROM and just plugging it in too, not only BASIC. I would even more appreciate it if such a card could hold more than one EPROM which could be put at different addresses and/or be enabled or disabled individually.
Paul


Am I mistaken, but isn't there already basic for the KIM1?
It seems like I've read something about this somewhere....

Here is Hanso's post on getting BASIC running
http://www.brielcomputers.com/phpBB3/viewtopic.php?f=16&t=293

Here is a reference to TinyBASIC running on the KIM1, but not the actual code :(
https://www.princeton.edu/~achaney/tmve/wiki100k/docs/KIM-1.html
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Re: Micro-KIM EPROM expansion?

Postby Paul Förster » Feb Wed 11, 2015 12:39 pm

Hi Jac,

jac_goudsmit wrote:It would be even better to have an EEPROM such as the 28C256 (32KB, less than $8) so you don't need an EPROM burner or UV eraser; the 6502 on the MicroKim will be able to write data to it as if it's a RAM chip. If the hardware design is done in a smart way, it will be possible for the 6502 to copy data from the motherboard EPROM to the expansion EEPROM.

I've been playing with a couple of ideas like that in my head for a while, but there are many other things that demand my attention. However I just put an order in to Mouser for replacements of my MicroKim RAM chips which have been broken for a long time. Maybe I'll get to it soon.


well, an EPROM would "feel" more like the olden days than an EEPROM would. ;-) But then, I don't mind as long as anybody would design/build one. :-) It would be cool if it would eat the space from $9000 to $ffff. In this case there'd be enough room for any kind of ROM code, i.e. BASIC, an ML monitor, etc. and still it wouldn't conflict with the 32K RAM card.

If you would make that happen then I'd buy one from you instantly. :-)

Cheers,

Paul
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Re: Micro-KIM EPROM expansion?

Postby Paul Förster » Feb Wed 11, 2015 12:42 pm

Hi Cappy 2112,

cappy2112 wrote:BTW- is there a monitor in the Microkim?


depends on what you call a "monitor". If you refer to a real ML monitor that accepts mnemonics and also decodes memory contents to mnemonic code, then no, there's none. If you refer to the possibility to view and edit raw hex data, then yes, there is. But the latter is very primitive to put it mildly.

Cheers,

Paul
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Re: Micro-KIM EPROM expansion?

Postby Paul Förster » Feb Wed 11, 2015 12:50 pm

Hi Cappy 2112,

cappy2112 wrote:Am I mistaken, but isn't there already basic for the KIM1?
It seems like I've read something about this somewhere....

yes, there is. There's both TinyBASIC and Microsoft BASIC.

cappy2112 wrote:Here is a reference to TinyBASIC running on the KIM1, but not the actual code :(
https://www.princeton.edu/~achaney/tmve/wiki100k/docs/KIM-1.html

I have an 8K file which contains a TiniBASIC paper tape. If you want it then I can post it here (if that's allowed, that is...)

Cheers,

Paul
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Re: Micro-KIM EPROM expansion?

Postby cappy2112 » Feb Wed 11, 2015 7:34 pm

Paul Förster wrote:Hi Cappy 2112,

cappy2112 wrote:Am I mistaken, but isn't there already basic for the KIM1?
It seems like I've read something about this somewhere....

yes, there is. There's both TinyBASIC and Microsoft BASIC.

cappy2112 wrote:Here is a reference to TinyBASIC running on the KIM1, but not the actual code :(
https://www.princeton.edu/~achaney/tmve/wiki100k/docs/KIM-1.html

I have an 8K file which contains a TiniBASIC paper tape. If you want it then I can post it here (if that's allowed, that is...)

Cheers,

Paul


Yes- please post a link.

I'm still confused. If you have Tiny BASIC, why go to the trouble of porting the C64 BASIC to the MicroKIM?
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Re: Micro-KIM EPROM expansion?

Postby cappy2112 » Feb Wed 11, 2015 7:39 pm

Paul Förster wrote:Hi Cappy 2112,

cappy2112 wrote:Am I mistaken, but isn't there already basic for the KIM1?
It seems like I've read something about this somewhere....

yes, there is. There's both TinyBASIC and Microsoft BASIC.

cappy2112 wrote:Here is a reference to TinyBASIC running on the KIM1, but not the actual code :(
https://www.princeton.edu/~achaney/tmve/wiki100k/docs/KIM-1.html

I have an 8K file which contains a TiniBASIC paper tape. If you want it then I can post it here (if that's allowed, that is...)

Cheers,

Paul


BASIC & Monitor for the SIM-1. I would expect that it should be mostly compatible with the KIM-1, but some changes would need to be made.
http://www.6502.org/trainers/synertek/
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Re: Micro-KIM EPROM expansion?

Postby Paul Förster » Feb Wed 11, 2015 7:44 pm

Hi Cappy2112,

cappy2112 wrote:Yes- please post a link.
I'm still confused. If you have Tiny BASIC, why go to the trouble of porting the C64 BASIC to the MicroKIM?

I don't have the link anymore. I found it somewhere on the net after doing a pretty extensive search. Send me your email address as a PM and I will send you both Tiny BASIC and instructions to that address.

Btw., I also have MS BASIC lying around here somewhere. I even managed to make it run once.

Why C64 BASIC? Well, that's what I know. In fact, I'm not interested in a particular BASIC. It's the full screen editing that the Commodore BASIC provides which makes me want it ported to the KIM-1 or Micro-KIM.

Cheers,

Paul

P.S.: I forgot: Tiny BASIC is integer only, no floating point numbers!
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Re: Micro-KIM EPROM expansion?

Postby jac_goudsmit » Feb Mon 16, 2015 8:03 pm

Paul Förster wrote:well, an EPROM would "feel" more like the olden days than an EEPROM would. ;-) But then, I don't mind as long as anybody would design/build one. :-) It would be cool if it would eat the space from $9000 to $ffff. In this case there'd be enough room for any kind of ROM code, i.e. BASIC, an ML monitor, etc. and still it wouldn't conflict with the 32K RAM card.

If you would make that happen then I'd buy one from you instantly. :-)

Cheers,

Paul


As an update to what I said originally: I got my RAM chip and hooked up my MicroKim to my Logic Analyzer last week. I tried various different 6502 and 6532 chips in combination with the new 6264 chip and the original one that I got with the board, and I couldn't get it to work. I also tried taking the 6532 and 6264 off so there was nothing on the address and data bus besides the 6502 and the EPROM. What I saw was that at the time when the clock was going low, sometimes the EPROM wasn't putting the correct data byte on the databus. So it looks like my EPROM got partially erased (I never bothered to cover up the window though I know I should) or is malfunctioning. I don't have an EPROM burner so I think what I'll try next is to connect a breadboarded Propeller to the expansion port to emulate the ROM, to see if it will "light up" that way.

Emulation of ROM/RAM using a Propeller is very easy to do at 1MHz (see the Superboard III project on this website, or my Propeddle or L-Star projects on Github). And updating the ROM image is as easy as changing a file name in the Propeller source code, and hitting a button to upload it. And if you would like an implementation with an EEPROM or a battery-backed RAM, it would only be a small step from the Propeller circuit.

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Re: Micro-KIM EPROM expansion?

Postby Paul Förster » Feb Tue 17, 2015 3:11 pm

Hi Jac,

thanks for the update.

jac_goudsmit wrote:What I saw was that at the time when the clock was going low, sometimes the EPROM wasn't putting the correct data byte on the databus. So it looks like my EPROM got partially erased (I never bothered to cover up the window though I know I should) or is malfunctioning. I don't have an EPROM burner

I did accidentally erased my EPROM once and Vince was so nice and help me out by sending the ROM image file so I could burn another EPROM. I can either send you the ROM file or burn an EPROM and send it to you if you like. Note however, if you choose the latter option, it'll come from Switzerland, so shipping would take some time. ;-)

Hope this helps.

Cheers,

Paul
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