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acadiel

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Posts posted by acadiel


  1. This might be something we can recreate the logic for to create reproduction CRU banked carts with current PAL/GALs.  The CRU writes are pretty simple.  We'd just have to figure out DBT's pinout on the cartridge (what they have hooked to where).  I did pinout the TI Workshop cart at one time (earlier in this thread) - I have no idea why it had all almost all the cart address lines on it for the PAL, but I'm gathering it only manipulated three of them.  


  2. 50 minutes ago, mizapf said:

    The custom Hexbus chip (above the EPROM with the yellow sticker) looks like the one on the HX5102 (hexbus floppy drive). This would be great, because it would make it simpler for me to write an emulation for this Hexbus interface.

     

    Ksarul bought hundreds of the Hexbus chips.  I forgot the exact number.

     

    • Like 1

  3. 39 minutes ago, brain said:

    Isn't there a HexBus Adapter for the 4/A That could be copied to do this?

    Yeppers!  That's what I was referring to above.  Ksarul has most of the copies of the /4A interface.  We also have schematics for the Hexbus drive controller.

     

    Edit:  These are the only pictures I have of the interface.  Ksarul will need to provide any higher resolution ones we need.  He also has tons of the Hexbus interface chips he got as surplus.  I do see a PAL.  I do have the ROM dumped (attached).

     

    DF3773FB-B5F0-46E8-A886-AB4A1834DF3D_1_105_c.jpeg

    A86664A3-465A-49F7-BF76-981000BEF7E6_1_105_c.jpeg

    2EFC4886-BB7C-4F07-B6A3-7C5308319F1C_1_105_c.jpeg

    3E6C1507-F394-4C9B-A976-D98390FAA4E6_1_105_c.jpeg

    4BA340B3-C7AF-415C-99FC-9900AFC32D1C_1_105_c.jpeg

    53993228-BBB3-4096-98A4-37E6FD5DC4B0_1_105_c.jpeg

    2903AA98-3910-40DA-BF91-3015F7BD7C9F_1_105_c.jpeg

    2FE74056-540E-4D29-B562-7C516FC6DE8B_1_105_c.jpeg

    D5F15599-A466-4B84-8A68-8FD9635EEC18_1_105_c.jpeg

    41DB7D31-D3FA-4B04-B945-AA2FA4163DE8_1_105_c.jpeg

    EB87A210-42FA-4E73-B0EA-A0B0D73FBF05_1_105_c.jpeg

    FDA5728F-1773-49A1-B276-296D776CE138_1_105_c.jpeg

    hexbus_interface.BIN

    • Like 3

  4. I know Ksarul has a lot of the /4A Hexbus prototypes (and I have the ROM for one of them).  But, has anyone thought about seeing if we can maybe put one of these in a sidecar for the JediMatt board?  It would be kinda cool to use these to use Hexbus peripherals, connect to a CC-40 or TI-74, etc.

     

    I'd be willing to partner with someone on it - but we'd need hires pics of the Hexbus sidecars in existence.  

     

     

    • Like 3

  5. On 5/1/2020 at 1:28 PM, pixelpedant said:

    There's a pretty large library of games with 9918 graphics (and often SN76489 sound) which have never gotten a TI-99 release.  Games for SG-1000/SC-3000, MSX1, Colecovision/ADAM, etc.  So generally Z80 based systems.  What games with ready-to-go 9918 graphics (and possibly SN76489 sound) do you wish could get a TI-99 port? 

    Door Door.  Someone did a ColecoVision port of it, I believe.  I can't find the video offhand.

     

    Edit: Here it is: 

     

     

    • Like 3

  6. On 5/4/2020 at 2:27 AM, Kchula-Rrit said:

    Nothing to do with the chip, but a funny coincidence.  While going through some old papers yesterday I ran across a receipt from Unicorn Electronics for some 74612s I had ordered some years ago.  Was wondering if they were still around; sounds like they are...

     

    K-R.

    Yep, just got some 2532A's from them!


  7. 9 hours ago, retroclouds said:

    That’s a very nice demo. 

     

    So there only seem to be system ROM chips and no GROM chips. Is there any GPL in the TI-99/2 ?

    I mean is the TI-Basic interpreter rewritten in assembly language?  If yes, this raises a couple of questions:

    • How does TI-Basic execution speed on the TI-99/2 compare with TI-Basic on the TI-99/4a ?
    • Did any source code for the TI-99/2 system ROMs ever appear?
    • Is the TI-Basic on the TI-99/2 a stripped down version of the 99/4a TI-Basic? I presume some commands do not exist (call color,..)

    The speed is much faster.  The standard For X=1 to 10000;print x loop runs much faster. 
     

    We have the hex dumps for the roms.  At least the 32K ones.  I don’t know if source exists.  I’ve spoken with all four parties that programmed the ROM software.  Three do not have the source.  The fourth is not sure what they have, and won’t know until they go back home (from their second Vacation home) in June.
     

    And yes, it’s stripped down.  All screen character definition, color, and sound is taken out.  There is added PEEK, POKE, and MHCL (execute machine language) instructions.  I’m sure if someone disassembles they rom, they can compare the BASIC tokens to the 99/4A. 
     

    If someone has any thoughts on solving why the unit can’t stand the mic and earphone plugs being plugged in at the same time, l’m all ears.  I keep getting an Internal Error when I have both plugged in to the battery operated cassette.

    • Like 1

  8. 18 minutes ago, mizapf said:

    Why not? The address bus, data bus, MEMEM, and DBIN are there.

     

    - Take one 2K SRAM for C000-DFFF

    - Take one 4K SRAM for 8000-BFFF

     

    Decode chip select for the 2K as (A0,A1,A2) = (1,1,0)

    Decode chip select for the 4K as (A0,A1) = (1,0)

    I didn't phrase my question correctly.  If this port is like the /4A's expansion port, the address space of >6000->7FFF is already decoded there.  You simply have to hook a SRAM up to the address pins and the data pins.

     

    I wonder if they did this on the 99/2's expansion connector as well to keep the component count for cartridges low - if they already pre-decoded the address space, they could just plop a ROM on a PCB and get away with no chip select logic.

     

    Edit, I found some notes here from one of the technical manuals.  However, these tech manuals were written at a time when this was a 12K ROM unit, not a 32K ROM unit.  

     

    We have 4K RAM, so the whole of >E000->EFFF is 4K of RAM.  The picture below assumed 2K of RAM, so >E7FF downward would be counted as RAM, down to >6800.  That tells me the 32K "expansion" they originally wanted on the expansion bus (>6800->E7FF).   However, since they added the extra 2K of internal RAM, does that mean only 30K can be on the expansion bus?  (>6800->DFFF)?  Or, can it continue to "count down" two more kilobytes to be 32K from >6000->DFFF?

     

    Anyway, I have the card edge connector and the 32K SRAM.  I just need some help designing a circuit if I do need to decode any address space here.  I figure we could start simple and just plop the whole 32K down from >6000->DFFF and see what happens.  There's nothing in that space anyway.  The last system ROM is located at >4000->5FFF.

    expansionram.png

    ROM.png


  9. Here is my best effort pinout for the 99/2, according to the schematic.  I've already found that the power supply (pre-regulator side) for the schematic is not  accurate for my system (the schematic shows an AC supply - I most definitely have an AC supply that is regulated down to 5V, and needs 7V DC minimum to get the regulator to run).  Seeing the 15V pins (33 and 34) that really aren't hooked to anything else makes me wonder if the 99/2's original PSU was a 15V supply, regulated down to 5V.  (I've been running 7.5V on mine without issue.)

     

    I wonder how to properly plop a 5V 32K SRAM memory chip on this expansion bus.  In other words, does the >6000->DFFF space exist on this expansion board?  Anybody want to take a guess?

    PIN	NAME
    1	GND
    2	GND
    3	GND
    4	GND
    5	DCIN (5V)
    6	DCIN (5V)
    7	DCIN (5V)
    8	DCIN (5V)
    9	DCIN (5V)
    10	DCIN (5V)
    11	HORSYNC
    12	COMP VIDEO
    13	A8
    14	A7
    15	A6
    16	A5
    17	A4
    18	A3
    19	A2
    20	A1
    21	CRUOUT/A0
    22	A9
    23	NC
    24	NC
    25	A10
    26	A11
    27	A12
    28	A13
    29	A14
    30	A15
    31	D7
    32	D6
    33	15V
    34	15V
    35	D0
    36	D1
    37	D2
    38	D3
    39	D4
    40	D5
    41	CRUIN
    42	CLKOUT
    43	ROMEN
    44	RESET IN
    45	INT1 (low)
    46	HOLDA
    47	HOLD (low)
    48	DBIN
    49	MEMEN
    50	W/CRUCLK (low)
    51	RESET (low)
    52	READY
    53	NMI
    54	CRTC CLK 3.35MHZ
    55	VERSYNC
    56	VIDEN
    57	GND
    58	GND
    59	GND
    60	GND

     

    (Left rear of unit)                                                            (Right rear of unit)
                                                TOP OF UNIT
        +-------------------------------------------------------------------------------------------+
        | 60 58 56 54 52 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 08 06 04 02 | 
        | 59 57 55 53 51 49 47 45 43 41 39 37 35 33 31 29 27 25 23 21 19 17 15 13 11 09 07 05 03 01 |
        +-------------------------------------------------------------------------------------------+
    

     


  10. A question for Michael Zapf about the 99/2 emulation:

     

    If we give the emulation 32K of RAM from >6000 to >DFFF, would the system would recognize all of it?  We can do that standard A=A+8 test to see if it does.

     

    That'll be a good indication if we put the 32K chip between >6000 and >DFFF on a real system how it'll expand the RAM or not.

     


  11. Here is the dead bug reference For the bank switched >4000 ROM.  The Test points circled in the diagram are defined on the top (CF40058 chip) and the connections to the 74Ls139N are noted in the bottom box.

     

    Note:  CF40058 is likely the I/O chip.  The only documentation available is for the CF40051, likely an earlier model.  The CF40051 shows pin #18 (TP1) being "S0/Keyboard Scan" and pin #20 (TP2) being "CRUCLKB (CRU Clock)."  How those play into bank switching, I don't know.  I do know that TP3 is a chip enable that will enable or disable that top EPROM.  I'm guessing that one of the cut traces goes to the bottom EPROM's chip enable, but I haven't metered that yet.

     

    42AB14D3-93C7-4D0C-AC29-5E5CCAE86436.jpeg

    • Like 4

  12. Stay tuned in this thread for a bunch of TI-99/2 information.

     

    Ksarul knows what I'm talking about... :)

     

    In the meantime, here are some tidits:

    • I am in possession of TI-99/2 unit #115.
    • This unit was originally going to be a Canadian demo unit, and is a almost production ready TI-99/2
    • The unit has 32K of ROM (attached), which Michael Zapf has confirmed is the same exact dumps as Klaus' 32K ROM
      • The system was originally supposed to have a 24K ROM (three EPROMs).  There is a 74LS139N logic chip installed 'dead bug' to enable bank switching at >4000 for 16K of the System ROM (8K at a time.)  I do have the pinouts of how this chip is hooked up.  I'll have to scan them.
      • The earliest specs for the computer said it would have 12K of ROM.  
    • The unit had two problems with it when I got it: 
      • 1) One of the bank switched >4000 ROMs was 'empty' - the TMS2564 voltage pin wasn't working, showing a null ROM.  Jumping bad pin 28(VCC) to 26 (also VCC) activated it. I programmed a new TMS2564 and installed it with the original sticker.
      • 2) The coupling 100nf glass capacitor near the power supply entry was shattered.  I bought a lot of 104 caps on eBay and installed a NOS one to keep the system authentic.
    • The system can run just fine off of a 7.5v, 2.5A DC power adapter.  The schematics for mine originally showed an AC PSU, but this most definitely uses a DC PSU, and has a 5V regulator inline.
    • The OLD CS1 and SAVE CS1 work just fine.  I was able to save and load to cassette.
      • The TI-99/2 does NOT tolerate stereo patch cables.  Use a mono one for both in/out
    • The system appears to have 4K of RAM.  If we can find a female cartridge connector, we might be able to PCB a RAM expansion.  We just have to figure out how much RAM the system will support in total.
      • The Memory map looks like this:
        • >0000->1FFF - System ROM
        • >2000->3FFF - System ROM
        • >4000->5FFF - System ROM (bank switched)
        • >6000->DFFF- My guess is that cart RAM/ROM expansion might live here (32K)
        • >E000->EFFF - System ram (4K)?
        • >F000->FFFF - Processor RAM and unused according to the memory map
    • The system has two custom IC's - CF40058 and CF40059.   These handle the Video Display Controller and I/O.   However, existing documentation for this system shows these two have different part numbers, CF40051 (I/O) and CF40052 (VDC).  I don't know which is which, but my guess is the 40059 is video (below the 9995) and 40058 is the I/O, because the dead bug for bank switching should be connected to the 40058.

     

    Anyway, stay tuned to this thread.  I have some surprises coming.

     

    94554460_1459967800844581_8638126835185483776_n.jpg

    94436285_1583979475087466_2272913980286566400_n.jpg

    jons_992_correct.zip

    • Like 14
    • Thanks 1

  13. Before the CC-40 and Waftertape drives were cancelled, the Consumer Products division had ready to release many BASIC programs that covered a gamut of Engineering and Mathematics topics.  I hereby present to you this list, which is unreleased, but now known thanks to an interview that Ksarul and I had last night with one of the last TI engineers that used to work in Lubbock on the CC-40 and TI-74 systems.

     

    I am investigating seeing if I can get permission to get these released from TI to the community.

     

    Control Charts
       PCHART
       P OR NP
       RANGE
       STDDV
       UCHART
       U OR C

    Dynamics
       CIRCLE
       COLLIDE
       INERTIA
       LINEAR
       PROJ
       ROTATE
       SHM
       VECTOR

    Electrical Engineering
       AMP
       BIPOLE
       COIL
       DELTA
       FIELD
       LDFLOW
       POWER
       RADIAL
       VOLT

    Extras
       CONVERSN
       KNMATIC1
       KNMATIC2
       ORBIT

    Inventory (control and management)
       EOQ
       LATE
       OVHD
       PGMT
       RT
       SUM
       TOTAL

    Non Parametric Stat
       CHISQR
       COCHRAN
       FRIEDMAN
       GAUSS
       KRUSWALL
       RANK
       RANKSUB
       RUNS
       RXC
       TAU
       TOLLIM

    PDraw (pen plotter drawing)
       CEDIT
       EDIT
       PERTRAN
       PLOTTERS
       TDEE
       TIMED

    Photo (darkroom and film exposure/processing)
       BW
       COLOR
       DEPTH
       EXTUBE
       FLASH
       LRATIO
       SLENS

    Pipe (Flow, etc)
       DWE
       EPM
       GLPS
       HCM
       HTC
       HTIP
       HWF
       WPD

    ProdPlan (production planning)
       BAL
       BREAK
       CAP
       CP
       CV
       RATES
       TIME
       TV

    Profit
       ATCF
       IRRA
       IRRB
       MDS
       NPVA
       NPVB

    Regression
       ADV
       AUTO
       CHECK
       CORR
       CORR2
       CUBIC
       EXP
       EXP2
       MLT
       MLT2
       NL
       WAFER (utility)

    Samples
       AOQL
       CONT
       DES
       SAM
       UNIT
       VARI

    Solar
       FCHART
       GAIN
       HEAT
       HEATEXC
       HTC
       SOLECO
       ZENITH

    Thermodynamics
       BDPOINT
       FLOW
       HEATCAP
       PENG
       PSY
       REACT
       SRK
       STEAM

    WaferTape Utiliities (for building cartridge images, etc mostly ram-loadable asm utilities)
       CARTDIR
       CARTINIT
       CARTLOAD
       CARTSAVE
       CARTSAVX
       DIR
       FILECOPY
       PROG
       SUBPROG
       TAPECOPY

     
     
    • Like 6
    • Thanks 1
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