FarmerPotato

I'm just reluctant to send my working Geneve anywhere. My non-booting one has only been plugged into a pbox under ordinary circumstances since it was last working in 2012. It's got one of the RAM mods (done by you know who) but not full GenMod. For some reason now it never lights up any disk controller card (TI, Myarc) and then complains it can't find a boot disk. (That gives me an idea just now to check what's wrong with it.) If I really have to, I'll send my good Geneve out..

I have a non-booting Geneve then, if it benefits your effort I think it's the answer. I will ask for a board level scan and a focus on the gate array. Although the TMS9995 and TMS9938 would be interesting.

If we could get a high quality xray of a piece of hardware, which one would we benefit from the most? Like this xray of the iPhone X here, in Step 3: https://www.ifixit.com/Teardown/iPhone+X+Teardown/98975 The huge photo: https://d3nevzfk7ii3be.cloudfront.net/igi/vtTlUFgswejlkdW6.huge I'm not just speculating. The engineer who produced that xray made me this offer. I'm thinking, the 4 layer PCB for the Geneve. I don't know if individual chips would be useful.. think of reverse engineering LSI. I wonder if the Geneve gate array would reveal useful info?

Beery, Back in the day, Genprog's LINK tool was useful for making cartridge images. It might not fit your use case. But if one has a lot of relocatable or absolute object files and wants them organized in cartridge banks or PGM files for use on a 4A, the process can be scripted.

I should clarify, my RDBENA* is internal to my side port thingy, not connected to a Pbox or anything else. I named it because I think it duplicates the same function as the RDBENA* in the flex hose. It turns on my 245 which connects to the databus at the sideport. If I were making a PBOX card I think I would just call it OE on the board. My problem was "fixed" by replacing R1 and C1. I replaced the 0603 pull-up resistor that read 10k with an 0805 3.3k. There is still a 0.7V drop across R1, which makes 2.5V into CE* suffficient. 1.6V was not! I think I may have a slightly damaged LVC245A sucking too much current, but today it passes tests. I don't observe any voltage drop across the same circuit , pull up resistor R2, connected to the CE* on another LVC245A. BTW, I didn't see any reason to use 244s, I think the 245A pinout simplifies my board when used in one direction only. Hopefully getting closer to a public announcement of a working board... Matt, I am definitely taking your suggestion of daisy chaining onto your 32k sidecar pins. It adds so much value to coexist with a TIPI. I have your 32k sidecar to begin with, and I'll order a TIPI when I actually have time to use it. -Erik

Update: I replaced R1 with a 0805 3.3k. Tested all the continuity. There is still a voltage drop across pull-up resistor R1. It supplies 2.4V to CE* on the LVC245A (still not 3.3V) when nothing else is driving CE*. This might be adequate. I suspect the LVC245A might be damaged and sinking 3ma into CE. I measured total current at the power supply at 10mA, which seems large. Stuart, I messaged you a link to a schematic.

It's attached to the side port. I am using the LVC245A as a level translator. It tolerates 5V inputs, and as for output, the VOH is 3.3V and is sufficient to pull TTL high.

I don't have extensive experience debugging hardware, so I'm asking for help with this little problem in my first surface mount build. In this circuit, as built by me, the pull-up resistor R1 to RDBENA* is not accomplishing its job. The LVC245A starts driving when VCC is applied. It's connected to the 4A sideport data bus, so disaster ensues. When I drive RDBENA* to 0 or 1 along with DBDIR, the board works ok. I'm wondering how to explain the measurements before I start over and reflow the parts. U1: VCC --- C1 --- GND DBDIR --- BDBDIR CE* --- R1 --- VCC \-- RDBENA* Spec Values: U1 LVC245A (SOIC 0.05" spacing) C1 0.1 uF smd 0603 R1 3.3K smd 0603 I hate 0603s. I'm switching to 1206. Measured values: C1 0.099 uF R1 9.9K R2 3.3K (elsewhere in another pull-up) Voltage measurements with RDBENA driver set to hi-Z: VCC 3.3V R1 1.6V measured at left side of R1 RDBENA* 1.6V measured off-board CE* 1.5V measured at chip leg So the pull-up resistor R1 is not accomplishing its job. Is it a bad solder joint? I verfied continuity between each lead. The measured resistance of 10K is strange - my R2 was 3.3K from the same reel. Ideas: 1. Is RDBENA* 1.6V consistent with it being an unconnected, floating input? 2. Is R1 damaged by my sloppy soldering, making it 10K? 3. Is there not enough current to pull CE* high? From the LVC245A spec, it only needs <0.01 mA. There should still be 0.33 mA available into CE* 1.7V drop over R1 would be 0.17mA flowing. This doesn't make sense. 4. Could the 9.9K measured at R1 instead be the resistance from VCC through U1 to CE*? 5. My VCC traces are the same size as every other signal trace. Should they be bigger? (I do have a ground plane fill.) 6. I'm leaning toward the theory that left lead of R1 is not connected... except my continuity check tells me it is. Maybe I'm probing the board trace, not the resistor? 7. Suppose R1 is completely destroyed. How much heat would it take to destroy an 0603 resistor?

Ick. Who wants to put identical cartridges up on eBay at reasonable prices?

Welcome! I am a CC-40 fan too but currently inactive. Did you go to VCF Atlanta? I think that's when Jim Brain and Jon Guidry hatched the SD plan. I know Jim from many VCFMW, the most relaxing of the shows.

I've got a Plan9/Inferno boxed copy and I admire the "everything is a socket" concept.

Suggest to the seller that he use your $250 to buy a nice flat panel display or a new phone BUT have it sent in a bubble mailer, instead of a cardboard box.

I hate scrolling pinball. I double hate the new video multi-pinball that have a 60" LCD screen in the form of an actual pinball field, and they still feel the need to scroll.

Well that was fun. Who won? I bid only $25 early on.

A variation on BLWP (from FORTI's interrupt service routine) LI R1,$+8 MOV *SP,R0 BLWP R0 * PC continues here: BLWP takes WP from R0, PC from R1, This gets a workspace pointer from the FORTH stack and performs an approximation of LWP, a TMS9995 instruction, on the TMS9900. It's used to run the same routine on different workspace contexts. Afterward you can put a return address in R14. CLR *SP set status LI R14,NEXT RTWP

I got through the first few years of college typing everything in MyWord. Then there is Fast-Term for Geneve (FTG) which operates perfectly at 9600 baud. I used this a lot to connect to Unix systems. Curiously, FTG has convenient key bindings for the Michigan Terminal System on the IBM/9000 mainframe, and the DELETE key sends the escape sequence for the PDP-11 network gateways in use in 1987 at Rensselaer Polytechnic Institute (Paul Charlton's alma mater.)

Yep, this is my go-to FORTH book since I got the bound copy. I use the pdf while traveling. Though I'm still retro-stuck in TI FORTH. That will change this week when I get plenty of FORTH time.

I've been a fan of FRAM ever since I wandered by the lab door of RamTron at UCCS. Texas Instruments has licensed it and brought it into the mainstream after 30 years. Here is a neat TI LaunchPad board with '430 CPU with on-chip FRAM that can run several flavors of FORTH. It often goes on sale for $4.30 http://www.ti.com/tool/MSP-EXP430FR2433

I see $0.20 each or 0.25 after shipping for the eBay auction. Still a good deal. For comparison, The PDIP-N HCT688 is available from TI direct for $0.75 or 0.53 in qty 100. SOIC HCT688 is $0.90, or 0.45 in qty 100. http://www.ti.com/product/CD74HCT688/samplebuy

Here's the rather bland official page. Shows more than the eBay listing (minus the $700 price. FYI the last eBay auction went unsold at $1600.) This unit is going to last me many more years. http://www.ni.com/en-us/support/model.vb-8012.html TechShop had many of these rolled out in US locations before they shut down. I wonder if those made their way onto the surplus market. The question is, if Tursi thinks his $350 logic probe was overpriced (and I think it looks like pretty good value!) where the heck can you get one at that level of performance? My Red Pitaya promised "open instruments" in 2014 but it still cost that much by the time it shipped and I had to buy the logic analyzer add-on for $100 + $25 software license. Just the Zynq-7Z020 CPU/FPGA is $125 at DigiKey. Here is the Analog Discovery line I considered. $200-$350 for not much functionality. https://store.digilentinc.com/all-products/scopes-instruments/ The NI MY-RIO platform is nearly as capable as the VB-8012 as a logic analyzer (Same CPU, Fewer gates Xilinx Zynq-7Z010, and a lesser A/D still from Analog Devices) but lacks logic analyzer software. It has 40 digital I/Os on 3.3V. Some students at UT Austin were doing a logic analyzer app, but it seems to have disappeared. Student price is up to $535 now (used to be $350 at the UT ECE department when they first used it.) https://store.digilentinc.com/ni-myrio-student-edition/ Check out this list of cool instruments, including the Gabotronics XProtoLab Oscilloscope Watch that didn't ship. https://www.eetimes.com/document.asp?doc_id=1320482 The el cheapo 2 MSPS XProtoLab board from HardKernel is $30 with 8 digital inputs. ATMega 16MHz. https://wiki.odroid.com/accessory/development/xprotolab There is a $59 one from Gabotronics. http://www.gabotronics.com/oscilloscopes/xprotolab-portable.htm Disclaimer: I did work for NI during the period this VB-8012 was rolled out and I have a lot of Digilent stuff.

Self-indulgent post, because I already bought this listing: https://www.ebay.com/itm/National-Instruments-VirtualBench-VB-8012-New-Open-Box/113176169234 I have coveted this Virtualbench since using it in 2015. It has 34 logic analyzer inputs, 2 analog 100 MHz, function generator, multimeter, DC power supply (software controlled), protocol analysis etc. There's a favorable tear down here: http://thesignalpath.com/blogs/2015/08/23/national-instrument-virtualbench-review-teardown-experiments/ My best tool so far was a Red Pitaya 8 digital/2 analog logic analyzer/scope. https://www.redpitaya.com/ It was a Kickstarter in 2013. I was able to use the Red Pitaya logic analyzer to debug my port of the MeCrisp FORTH package from MyStorm to IceStorm v1 (watching the ARM M4 boot up and write debug chars to serial port), but I need a bigger logic analyzer. I like the logic analyzer that Tursi uses. http://www.pctestinstruments.com/ I considered buying one. But I have a crush on this VB-8012. Incidentally, a similar Zynq-7020 chip (ARM A9 CPU + Artix-7 FPGA) is used in VB and Red Pitaya.

This has gotten really off topic.

Hi Matt, Trivia: the Myarc Personality Card used crubase >1000 to intercept DSK1 etc. Probably the first example of doing so. I was lucky to have one, ca 1984, and a copy of BUGOUT, to poke around in the DSR ROM. That was my lesson on how DSRs worked. I agree with your idea on coexistence of peripherals. I use NanoPEB but it's a dead end. For myself, I would not want to make a device that plugged into your 32k expansion header AND clashed with the 32k space.

I like the themed contests. I would go for a SAMS contest, or a music contest. It would be more about encouraging people to develop ideas toward something maybe we don't have enough of, or don't know what we haven't seen yet (:

For INKEY$ and the like on other platforms, here is an article by our friend Regena in late 1987. https://www.atarimagazines.com/compute/issue89/The_Beginners_Page.php I'd like to think she wrote out the appropriate CALL KEY code for TI-99/4A, but that the Compute editor removed it. For those who weren't around then: C. Regena was a legendary magazine author, whose mystique was built up by the editor of 99er magazine with tales of how her prolific manuscripts arrived mysteriously signed only "Regena", while actually she was a well known writer for other computer magazines.