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About MarkO

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  • Birthday 04/07/1966

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    Albany, Oregon, USA, North Western Hemisphere, Planet Tera
  • Interests
    Computers, programming, OS/2, Open BSD, Bass Playing
  1. The 65816 can has a Stack a big as 64K, and As I Recall, using two Stack Pointers, you can ( relatively ) move Data from One Area of Memory to the Screen Buffer much quicker that with Loading and Storing the Accumulator. MarkO
  2. RetroChallenge 2018/09!!!!! Bring it On!!!! MarkO
  3. Just a Reminder... Next Weekend is VCF-West in Mountain View, CA..... Thomas Cherryholmes is doing a presentation about IRATA.ONLNE, right after Brian Dear's presentation on his book, "THE friendly ORANGE GLOW" I'm planning on attending!!! VCF-West Speakers MarkO
  4. I am an Old Apple ][ guy ( and Commodore SX-64 Guy ), but I have only got into the CoCo's 6 years ago... I got a CoCo 3, NIB with an Apple //e Platinum.. I thought about selling it, but the MC6809 was too cool to not try out.. ( If you find the MC6809 cool, wait until you find out about the HD6309.. ) Since that point, I have added a CoCo 2, another CoCo 2 with a CoCo 1, and another CoCo 2.. Two MPIs, Two CoCoSDCs, Two CoCoPSGs, and Two CoCoGMCs... And a couple FD-500s.. The MC6809 is a way more Capable CPU than the 65xx, even at .89Mhz, and the CoCo 3 you can Double that, and if you swap in the HD6309, you will move it up another notch in performance.. The CoCos have a 6 Bit DAC, that can make pretty nice sounding music, but it is very CPU Intensive... No Sprites, but the Stack Blast trick that can be done on the 65816 can be done on the MC6809/HD6309.. The Nuclear Green Screen is very Off Putting, but I think that was to keep the Casual Users away.... MarkO
  5. I just found out today on CoCoTALK! Episode #63, that initially the CoCo's Cartridges were not to rely on any of the ROMs in the CoCo, but later were allowed to access "certian" routines ( Functions )... Per Steve Bjork and then Mark Siegel both who wrote Cartridge Games for the CoCo, BITD... http://www.mobygames.com/developer/sheet/view/developerId,196778/ MarkO
  6. Agree... It has been discussed in the CoCo Areas, "Can Software detect the difference between a CoCo 1 and a CoCo 2?" Other than finding 4K of RAM, ( CoCo 1s Only ) or Standard BASIC v1.0, ( I am fairly sure that Standard BASIC was v1.1 by the time the CoCo 2 was shipping ), there doesn't seem to be a way to tell a CoCo 1 with 16K and Extended BASIC or a CoCo 1 with 64K and Extended BASIC and a CoCo 2 with the same RAM and BASIC.. Your CoCo 1 might have been upgraded to 64K, but the BASIC might not have been... Extended BASIC needs 16K at least, but Standard BASIC doesn't care... The Cartridge Games are written in Assembly Language, so the BASIC is not relevant... MarkO
  7. I am fairly new to CoCos too.. Electronically there isn't much difference between the Coco 1 and CoCo 2.. CoCo 3s have a lot of differences... The CoCo 1 has a 12VDC Supply plus the 5VDC... The CoCo 2 and 3 only have the 5VDC. The CoCo 1 came with Standard BASIC and if it had 16K or 32K ( and Later 64K ) it could have Extended BASIC. ( CoCo 1s were 4K or 16K and later were expandable to 32K, and once the White CoCo 1s came out they were 64K ) The CoCo 2 came with Standard BASIC and it could have Extended BASIC. ( CoCo 2s were 16K or 64K ) The early CoCo 1s had the Chiclet Keyboards.. The later 64K CoCo 1s came with the Lower Profile, ( meltey key ) Keyboards that the early CoCo 2s came with . The CoCo 2s were Cost Reduced, in that the Circuit Board was Smaller, so more CoCo 2 Motherboards can be made from the same size Sheet. Maybe and Maybe See Techno's Page for the Models and their Configurations.. MarkO
  8. I have an SX-64 as well as a couple C64's with the 1541's.. And a C128 with a C1571... I am trying to locate my RS-232 Cart.. I have some ESP8266 devices that will connect up to the RS-232 Cart, once I find it... I don't have a NIC for the C64 yet, but planning on getting one... I have some version of the Super CPU for the C64, but I have not tested it yet... MarkO
  9. Dave Phillipson ( programmer of an OS9 Level 2 program called Supercomm ) said: "Tell him the unravelled book has got it. He’s also got the start address wrong. It is $C000 not $C800. I just checked "DISK BASIC UNRAVELLED II" and it’s right there on page B2. The DIsk ROM is the same regardless of which model of CoCo." http://www.colorcomputerarchive.com/coco/Documents/Books/Unravelled%20Series/disk-basic-unravelled.pdf MarkO
  10. That is Strange... I did the same update, in the same manner on a friends Melted Key CoCo 2 and it worked fine... I would check all the Sockets and Pins looking for a Poor Connection.. If the Upper Address Lines were In-Op, the computer could not access the Upper RAM... MarkO
  11. Thanks for the Pictures.. If one of these needs to be built, we have the Circuit and Components.... MarkO
  12. A Resistor Key.... The Two Resistors are set to a particular value... The Values, when read let the Program know that it is a Valid Install, if the values are correct. MarkO
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