FarmerPotato

What are all the memory holes that a 512k card should leave unmapped? 1. with AMA,AMB,AMC high, >4000 (page >BA) 2. with AMA,AMB,AMC high, >8000 - 9fff for memory mapped peripherals like sound, speech? (page BC) 3. dip switch option to open holes at any AMA,AMB,AMC in case of any nonconforming card in PBOX Design Notes pages 80 - C0 are external 512K in pBOX AMC is most significant address line >BA must be a hole. This is >4000 in the top 64K. AMA,AMB,AMC are pulled high in the PBOX. DIP switch option to open the hole at >4000 for all values of AMA,AMB,AMC dsr = !a0 & a1 & !a2 mmap = a0 & !a1 & !a2 high = ama & amb & amc hole = (high | dip) & (dsr | mmap) https://www.mouser.com/datasheet/2/464/IDT_71V424_DST_20141030-881857.pdf CS* = memen* | hole OE* = memen* | dbin = dbin WE* = memen* | we* = we* http://www.ti.com/lit/ds/symlink/sn74lvc245a.pdf lcv245a to data bus: A side = SRAM B side = PBOX dir = memen* | dbin (high: A to B. low: B to A) oe* = memen* | hole lvc245a will output high level voltage 3.3V on data pins. This should be greater than VIH of the LS245 of the Geneve. Should be OK. all other input signals buffered one way through lvc245a

New build ocurred to me because I'm currently debugging 512K SAMS in a sidecar (it's killing reads from the module space when A9 is high). The vintage TMS4500 DRAM controller is on eBay for $5-$9, not to say DRAM itself. I checked Mouser last night.. A 512K x 8 SRAM in 3.3V is $4 for SOJ-36 1.27mm pitch. 71V424S12YG Add 4 of TI's LVC245A (they can do the job of a 244 too, and bridge 5V to 3.3V), a small PAL to block the reserved address pages, voltage regulator for 3,3V, caps and bingo. None of the chips would be socketed, Could probably even get PCB with assembly included for $50.

Another angle: is there a schematic for a Geneve only 512K expansion? It could be safer to make a card from scratch than modify a 4A card.

Actually, LBLA runs fine now. My sidecar project was fighting over the module ROM space. It is killing memory reads from the module ROM when address line A9 is high. So, every other 64 bytes is garbage. I noticed that the ROM ref/def table was partly trashed.

No, the SAMS scheme is TI's LS612 memory mapper, which does a direct substitution. SAMS replaces the the top 4 address bits with a long address. So you can only map 4k chunks to SAMS addresses. Also, TI put the memory-mapped peripherals and PAD at 8000-9FFF which breaks the flat memory model. It is unlikely that external hardware on the 4A could implement LDS and LDD for external memory... more likely on the TMS9995. On the TMS9995, LMF, LDS and LDD, 0320, 0780 and 07C0 resp, are trapped by the MID interrupt (Macro instruction Detection) which goes BLWP @0008. I find these 990 instructions fascinating in part because they were left in the port of the assembler for the 4A Editor/Assembler, I could see them in there back in the day with DISKO, but there was no documentation. I don't know exactly what the TMS9900 does with illegal opcodes.

My dad worked at the Lubbock plant from 1978 to 1985 in Educational Products, that is, Speak'n'Spell. There was an engineering recruiting effort to bring people to Lubbock from all over to Lubbock--we moved from San Jose, California. His boss in 1981 had been relocated from TI Amsterdam via TI Philippines. Lubbock was a great place to be a kid, maybe not such a great place to be a young adult, but the city's devotion to education and the arts was citizen-led and something to be proud of. My best friend's dad arrived in 1979, was a manager on a TI plastics line, and that lasted until 1987 or so, when he was transferred to Johnson City, TN. His mom worked as a 4A assembler and repair technician, then went back to teaching school when that ended. You might ask, unfortunately, as an employee did you feel excitement about home computers, or was it just a job? As a kid, it was weird finding copies of the 8080 Bugbook laying around in the shed, along with inscrutable 132-column printouts. After TI Lubbock closed down even more of the Consumer Products Division, we had been moved to TI in Colorado Springs. And it was even weirder finding a textbook on Cosmac and 9995 and other 16-bit processors, then a TMS9995 manual at a friend's house, next to Pringles cans full of "chips" (sadly, obsolete DTL). I figured, how hard could this digital electronics stuff be? and never looked back. I didn't know at the time that that friend's dad had been a manager on the 99/8. Other TI engineers from time to time would hear about me and randomly drop off little things, like a hard to find 10.737 MHz crystal, an eprom programmer, an old scope, a wire wrap gun, you know, things every teenager wants.

Bingo. LBLA Remastered loads from the headphone jack on my Mac. But, it doesn't run, just blank cyan screen.

I have not been able to get any of the LBLA.wav files to load into: Beige TI-99/4A with F18A. Mini Memory. Single cassette cable, white going to PC headphone jack. I have tried adjusting the volume, as in the old days, but no go. "Error - No Data Found" every time. Sigh. I am about to try to make an actual cassette out of it.

Packaging games was a bad deal for games studios and publishers by the mid 90s. A few distributors, a handful of catalog printing houses, and brick and mortar stores made the profits, leaving only a fraction of the street price to the publisher. Catalog houses like PCConnection/MacConnection might require 20,000 volume in warehouse and then sold (not returned or remaindered) before paying anything to the publisher. It was an environment geared to A-list million sellers. The situation didn't get much better with direct internet sales of boxes. Only downloadable, electronically unlocked copies made a difference to small publishers in the late 90s, as a majority got Internet. (and this model still piggybacked on CDROM magazines to get the demos out.) Packaging was something special, another opportunity to create art and artefact. If you can do it.

I downloaded the Unix V6 port for the TI-990 from http://www.cozx.com/dpitts/ti990.html I was interested in how the LMF "Load Map File" had been used in TI-990 O/S. LMF allows you to partition the 64K address space into 3 regions. Each region has a bias address register to where it maps into the 1MB extended address space. Each region has a limit address; the third region can end earlier than the top of memory. Access above the third region limit raises an error interrupt. v6/mmu_990.s is the memory mapping routines. It illustrates usages of the LMF, LDS, LDD instructions. LDS alters the address of the next source address, by loading a bias register to address the full 1MB. LDD alters the next destination address. The memory map used by mmu_990.s looks like: 0000 - 0fff 4k of kernel, biased to somewhere 1000 - efff 56k of user space, biased to somewhere f000 - f800 workspace and tiline peripherals (hard disk etc)

I agree with the Hilton Garden Inn, and calling it CTI Friday. As for signage, I propose a really big Parsec ship with glowing EL wire around the edges. A rangefinder sensor triggers a recording of "Alien Craft Approaching", or some more welcoming message. There will be no mistaking that you're in the right place. Here's my prototype:

I got to practice on a working Adam once. It was strange knowing it was a TMS9918, yet the BASIC command HPLOT matched AppleSoft.

Making CHI Friday that much more real: Opry99er contributed the sound track by playing Blasto, which is still running through my head. Great game, the first I bought with my own money after reading a Saturday morning store ad. Then OLD CS1 had the Munchman pause/reminder jingle on his phone ring tone. It's stuck in my head again after decades of hiding away.

I never looked in the Cassettes directory before. Under Mini Memory it looks like it contains copies of the LINES demo? I find myself in need of the Mini Memory Line by Line Assembler cassette. Recently I have been hand entering machine code into Easy Bug. If someone could add the wav file I could really use it. http://ftp.whtech.com/Cassettes/Mini_Memory/

I think 99'er Magazine October 1982 has an article about programming PILOT. Subsequent issues had some coverage too.

I have a mind to do a search program for LPC codes, against the Gauntlet ROMs for starters (it had a TMS5220.) I'll have to defer working on a TI sound survey for a bit. You can lift from games that have source code, and there is a SNDTEST collection that TI did (that's another story). As for learning C, I started with Clint Pulley's c99 tutorial and a bunch of Dr Dobb's magazines, but I would not recommend that. I am grateful for the Brian Kernighan books: The C Programming Language by Brian Kernighan The UNIX Programming Environment by Kernighan and Pike The C Standard Library by P.J. Plauger That was a long time ago, but, you would absorb more knowledge from that course than many others. These days we have fancy stuff like https://www.learn-c.org

From page 41 of the XB manual RELATIONAL EXPRESSIONS Relational expressions are most often used in the IF-THEN-ELSE statement, but may be used anywhere that numeric expressions are allowed. A relational expression has a value of -1 if it is true and a value of 0 if it is false Evaluate S=T-(T=770)*64 T T=770 *64 T-that === ===== === ===== 660 0 0 660 770 -1 -64 834 880 0 0 880

Everything after the ELSE is part of the ELSE statement2. You would need to start a new line after S=T. Or embed the comparison in a formula like this: 10 CALL CLEAR :: FOR T=110 TO 880 STEP 110 :: S=T-(T=770)*64 :: CALL SOUND(200,220,1,440,1,S,1):: NEXT T :: GOTO 10

Sound lists? Here you go. The linked code, sndsrch.c, guesses at what portions of a file are sound lists. It found 8 potential sounds. See advertsnds.txt for source. (I did not test the sounds.) There are some variants in the output file, because some guesses overlap. The program prints alternates in cases where a byte might be interpreted as either a count or a sound chip command. You will have to untangle them. It also prints 2-3 stray bytes in "holes" between almost contiguous sound lists. Several of these holes are >7E,>82. Is that GPL for play sound? Oh I think I get it.. this is at grom base 6000. S$1E82 is another list for silence then a tone.. 7E82 sure appears in there a lot. Hmm. Example: S$1E16 BYTE 7,>8E,>12,>90,>A8,>16,>B0,>DF,40 BYTE 2,>9F,>BF,30 BYTE 6,>8E,>12,>90,>A8,>16,>B0,60 BYTE 4,>82,>13,>AD,>16,8 BYTE 6,>87,>13,>91,>A2,>17,>B1,8 BYTE 4,>8B,>13,>A7,>17,8 BYTE 6,>80,>14,>92,>AD,>17,>B2,8 BYTE 4,>85,>14,>A3,>18,8 BYTE 6,>89,>14,>94,>A9,>18,>B4,8 BYTE 4,>8E,>14,>AF,>18,8 BYTE 6,>83,>15,>96,>A4,>19,>B6,8 BYTE 4,>88,>15,>AA,>19,8 BYTE 6,>8D,>15,>99,>A0,>1A,>B9,8 BYTE 4,>82,>16,>A6,>1A,8 BYTE 6,>88,>16,>9C,>AC,>1A,>BC,8 BYTE 0 M$1E80 BYTE >7E,>82 S$1E82 BYTE 3,>9F,>BF,>DF,0 BYTE 3,>86,>0D,>93,10 BYTE 0 https://raw.githubusercontent.com/olsone/forti/master/sndsrch.c https://raw.githubusercontent.com/olsone/forti/master/advertsnds.txt

Speaking of old diskette drives, Opry99 has the quietest Mitsumi half-height drive I have ever used. It was a D503. I thought it was quiet attached to the P-Box. But when we had the P-Box turned off, and the drive was attached to a modern laboratory bench supply and Kryoflux, it became ninja-like in its stealth, silently sucking 223 mA of 12V and slurping DSSD floppies faster than I could put them back in their sleeves. It's a pleasure to find the best of 1980s technology perfectly tuned.

The TI acoustic phone coupler looks great at public events. I park it next to the 99/4 display. Now that I have an RS232 sidecar, it's usable with TE2. It can connect "over the air" to another acoustic modem. What I don't have is an actual phone handset to show, which is almost as unknown to kids now.

The store display existed for the 99/4 as well. I remember many of them at Texas Instruments Lubbock public open house day in December of 1980. It was my first exposure to the 99/4. The display shown here is just about the same configuration. There must have been many more of the 99/4A store display in existence.

I'm at the Hilton Garden Inn. Sitting at the table outside the conference room.

I will be at the Hilton by 5pm - taking bus from O'Hare. How about just meeting in the hotel bar area?