What TI-99/4A-adjacent systems are you tempted to explore?

[Geoff Oltmans]

Well, depending upon adjacent to what facet, my vote would be the Coleco ADAM. Oh wait, I already do that one. ha

 

But out of your list, probably the Tutor.

[JB]

I've been interested in the MSX family for a while, in large part due to the shared VDP heritage.

[mutterminder]

I've got a couple of CC-40s, but I've not yet spent much time with them.  For a while I tried real hard to get an RS-232 interface, but I've just about given up on those as they are scarce, and when one come up for sale people are asking too much.   I also have a few TI-74s, I really love these little machines, and for a while I was using one as my main calculator.

[+FarmerPotato]

1 hour ago, mutterminder said:

 For a while I tried real hard to get an RS-232 interface, but I've just about given up on those as they are scarce, 

Occasionally, mdude puts a new one on eBay. They go back to the LL Conner inventory, which he in turn got wholesale from ?Broadworth? A TI dealer who bailed in 1985. (Notice published  in Smart Programmer). Which is pretty amazing. 
 

Do you have the modem? Easier to get.. crazy idea, you could hook it up to a serial  modem in a loop.  From Basic  the modem looks pretty much like the RS232.  
 

In 1984 I would carry the CC-40 and Modem on  road trips (was just a kid) with my list of local BBS. 
 

 

[JB]

13 hours ago, mutterminder said:

I've got a couple of CC-40s, but I've not yet spent much time with them.  For a while I tried real hard to get an RS-232 interface, but I've just about given up on those as they are scarce, and when one come up for sale people are asking too much.  

Could be worse. Imagine needing one of the three mass storage devices from the period. Two different floppy drives and the infamous wafertape drive, only one was ever actually sold, and all three are rare as hen's teeth. 

[mutterminder]

22 hours ago, FarmerPotato said:

 

Do you have the modem? Easier to get.. crazy idea, you could hook it up to a serial  modem in a loop.  From Basic  the modem looks pretty much like the RS232.  

I did see a modem for sale at PRGE and I was very tempted. But outside of the collectors value, it really wouldn't do me any good. I don't have a land-line anymore.  I don't know.  How would you use it? Will modems work with VOIP? If they do,  I guess I could have some crazy set-up with a modern PC serving as a BBS host over my home network.  But that's just crazy talk. 😁

[+OLD CS1]

7 hours ago, mutterminder said:

Will modems work with VOIP?

300 and 1200 bps modems should work find with most VoIP services.

 

7 hours ago, mutterminder said:

But that's just crazy talk. 😁

What we do around here.

 

[+arcadeshopper]

3 hours ago, mutterminder said:

I did see a modem for sale at PRGE and I was very tempted. But outside of the collectors value, it really wouldn't do me any good. I don't have a land-line anymore.  I don't know.  How would you use it? Will modems work with VOIP? If they do,  I guess I could have some crazy set-up with a modern PC serving as a BBS host over my home network.  But that's just crazy talk. 😁

thanks for stopping at my booth

 

I used it with fios voip here to call The Hidden Reef BBS: 

 

 

Also I understand the disk emulator HEX-ti-r works as a serial port as well as disk storage  I have them in my store right now out of stock as i catch up on orders but will have more soon if you want one lmk and I'll put one in stock for you

[Retrospect]

On 11/25/2022 at 3:03 AM, pixelpedant said:

Likewise.  After all, in the same years when a bunch of you were driving to work at the height of the home computer boom, I was driving nowhere (but fast!) on my Tomy Turbo:

 

 

But seriously, I think those things were rather exciting for about 20 seconds if you were the right age when they released (in 83 apparently).

 

Then it became clear that they don't really *do* much of anything. 

 

Pretty exciting for those 20 seconds though. 

I got one of these in 1985, here in the UK.  After about a year or so 4th gear refused to select without a fight.

[Tuxon86]

11 minutes ago, Retrospect said:

I got one of these in 1985, here in the UK.  After about a year or so 4th gear refused to select without a fight.

My 2005 Mazda 3 was the same... They had to replace the transmission twice under waranty...

[+OLD CS1]

3 hours ago, Tuxon86 said:

My 2005 Mazda 3 was the same... They had to replace the transmission twice under waranty...

Unfortunately, those old Tomys did not come with such a good power train warranty, but I have recently restored one of those things.  Sadly, my 2007 3 suffered a transmission failure at the ripe old age of 10 years and 153k miles.  Fortunately, it did not cost much to put a new tranny in it and I was able to give the car to my daughter.

[speccery]

On 11/25/2022 at 11:53 AM, speccery said:

Within the TMS9900 realm in addition to the TI-99/4A I'm interested in the Geneve, Tomy Tutor and the TI-99/2. Of course all three are based on the TMS-9995. @pnr made a FPGA version of the TI-99/2 (not sure if it's complete) and I have played with it. I find it interesting since it has a "normal" architecture: memory mapped frame buffer, no GROMs and I guess no GPL either. That architecture would be much better for BASIC. I just dug up the "TI992_Product_Specification.pdf" and indeed the memory layout is nice, no I/O devices breaking the memory map in the middle. Makes me think if I should build one myself, I recently acquired two more TMS9995 processors (still untested). Just use the existing spec and of course add color graphics  

 

Not that it matters to anyone else than me, but just want to share the two TMS9995 chips I recently purchased both seem to work perfectly. Tested these on the Mini Cortex board. Was nice to see boot message, I seem to have last working on the boot ROM in 2016 as that what the boot message says...

[+FarmerPotato]

On 11/25/2022 at 3:53 AM, speccery said:

. TI-99/2.  I find it interesting since it has a "normal" architecture: memory mapped frame buffer, no GROMs and I guess no GPL either. 

 

It may be clean, but since the VDP shares the main RAM , you get an ugly surprise. As you print more BASIC lines to the screen, the interpreter slows down. The VDP steals a lot of cycles from the 9995. This is mitigated by the VDP yielding when it encounters an end-of-line character (31). It  then emits blanks. Char definitions are mostly in ROM too. 
 

As I understand it, the 9918 consumed most of the memory bandwidth to provide sprites; the ASIC variant in the 99/2 consumes  a lot too. 

[speccery]

12 hours ago, FarmerPotato said:

It may be clean, but since the VDP shares the main RAM , you get an ugly surprise. As you print more BASIC lines to the screen, the interpreter slows down. The VDP steals a lot of cycles from the 9995. This is mitigated by the VDP yielding when it encounters an end-of-line character (31). It  then emits blanks. Char definitions are mostly in ROM too. 
 

As I understand it, the 9918 consumed most of the memory bandwidth to provide sprites; the ASIC variant in the 99/2 consumes  a lot too. 

Yes that's true, I was reading the technical description the other day and indeed it uses DMA cycles by asserting the DMA request and stealing the bus. This is in contrast to ZX Spectrum, VIC-20 or C64 which also steal cycles but for the most part it goes unnoticed, since the memory bus is effectively running at twice the speed of the CPU. Probably something similar could have been done with the 99/2, but with additional cost. Looking at the pictures in this thread the system is using HM6116LP-4 SRAM chips, which have a cycle time of 200 ns, thus from the viewpoint of RAM chip speed it would have been possible to multiplex the RAM between VDP and CPU. Of course one would have needed those multiplexers as additional cost.

[Appeelicious]

I am tempted to get one of those cc-40s. Mostly because there isn't much broken ground so I guess I'd feel like a pioneer. The only thing that stopped me 2 weeks ago was the hex-ti-r being out of stock. Which probably saved me from being chewed out