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Jeff White

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About Jeff White

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  1. Is the pissing match over Rich and Harry? I am afraid not. Thanks for your contribution, RedBaron!
  2. Maybe I am having a “senior” moment, but if you press 1 from the EA menu, does it not load an EA5 program EDIT1 etc, and if you press 2 does it not load EA5 program ASSM1 etc?
  3. I think word transfers with Genmod Geneve are possible with Rev E boards (upgraded or not), upgraded F and G boards, and upgraded ASCSI.
  4. Considering there are only 327 active 99/4A and/or 99/4A emulator users in the world and that most who wanted a copy received it, I do not consider it rare. But it is well done!
  5. Visit uspto.gov to read patents 4,286,320, RE31,977, and related patents.
  6. @InsaneMultitasker, does GenMod Geneve still need to use byte-transfer mode with SCSI cards that have the Becker upgrade?
  7. I think that CALL LOAD is just clearing the values for first free address (FFA) and last free address (LFA) of 24K to make it “disappear”. I am pretty sure that I was able to point the FFA and LFA using values in the range 2000-3FFF and manipulated some other values to CALL LOAD object code into 24K without using AORG. I had limited success. It made sense to do it at the time. I could be misremembering.
  8. It has been years since I looked at it, but I seem to recall that you can force XB to use high memory (A000-FFFF) for assembly and low memory (2000-3FFF) plus VRAM for XBASIC code. It takes some effort and probably breaks a few things.
  9. @SkyPilot, I keep seeing posts regarding a TI BASIC/TI Extended BASIC compiler. Yes, these BASIC’s are slow, but compiled? @tmop69? @senior_falcon?
  10. The best way to determine if a console is QI or not is to open it up and look at the motherboard. On the QI, much of the glue logic has been put into a single chip. Additionally, IIRC, the cartridge port is missing the ability to control the CRU.
  11. But that’s a good price… FOR ME TO POOP ON!
  12. Reading the 99/4(A) patents gives additional insight on GPL. How about a Forth written in GPL?
  13. @dhe, @InsaneMultitasker, @mizapf, here is the short explanation. The 53C80 is setup in such a way that by continually reading or writing the data register the handshake automatically occurs. In byte-transfer mode, the 53C80 only responds at the even address. In word-transfer mode, the 53C80 reponds to both even and odd addresses. By checking a CRU bit or reading a status register, it can be determined when the transfer can begin. To speed operation, multiple MOV(B) instructions can be used. The key here is that the SCSI drive buffers the complete sector contents, be it 256, 512, 1024, or 2048 bytes etc. One caveat with the 99/4A is that word-transfer mode requires swapping bytes because of the sTupId odd-byte before even-byte transfer.
  14. @Tursi, I think ABS is rarely used. Do we have a chart of instruction frequency? ABS is special. Is there any other assembly instruction that sets status bits on source operand?
  15. In reviewing how CLR @VDPSTA works on the 9900 versus 9995 and what @PeteE is trying to do, I thought about using ABS @VDPSTA instead which requires reading VDPSTA with both CPU’s. In reviewing ABS, I note that it is the original value (source operand) that sets the status register bits 0-4 and not the result. Is this how MAME, @mizapf, and Classic99, @Tursi, work?
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