cbmeeks

So would that be 150 ohms for all 8 locations?

Ah! So, any idea what needs to be in there? IIRC, there are 16 pins (8 jumper locations).

Hmm. I'm not quite sure I know what you mean. Although I have the manual, it's pretty light on schematics and details. It has a socket in for "shunt" type connections which the manual says is for selecting the drive number. However, it also has an empty socket next to it that I have no idea what it's for. My gut feeling tells me the drive is probably OK. I just don't have it configured properly. I know there's no practical reason to use a full height drive in 2020. I will only drag out the PEB for nostalgia anyway. ?

I appreciate the offer but I think I will either use two half-height or see if I can repair the Shugart. Thanks

I have another thread going about my floppy drive with my PEB but thought I would ask a different question here. In my struggles to make the floppy drive work, I noticed I accidentally bent pin 3 and destroyed it on my floppy drive controller. IIRC, this is just another ground pin and many cables have that pin blocked off (that's how I accidentally destroyed it). Now, I could easily replace the floppy connector if I needed to. But it doesn't seem to matter as I got two different drives to work. Is there any harm in leaving that pin broken off?

OK, good news and bad news. I think the culprit is that Shugart drive. That loud "clanking" sound when the drive heads clamp down sounds really loud. So I think the jumper settings are either wrong and/or the drive is just bad. Next I put a 3.5" 1.44 MiB drive in, located an old Amiga floppy and chose 40 tracks, single sided and single density and it formatted! Not only that, it passed the diagnostic tests. Which means the controller is good. Next, I dug out an old 5 1/4" drive (1.2 MiB) and sure enough, it worked as well! Naturally, the next move was to load the only TI-99/4A software I own on floppy disk. So I am super excited that after 38 YEARS, I finally have a floppy drive setup for my TI-99/4A. No more cassette saving for me! hahaha Now, I have to admit, I'm a little disappointed that my Shugart drive isn't working. I really wanted a single full height drive in that PEB. I do happen to have TWO 5 1/4" drives that are half-height. So I guess I could, in theory, install both of them. But they are beige in color. Not that it matters but I liked the look of the black face plate. Which brings me to some more questions. 1) Should I keep looking for a full-height drive to finally fulfill my dream PEB? 2) Should I use my last two 5 1/4" drives that are the wrong color. If so, would DSK2 work with the "twist" in the cable? 3) Should I do something crazy like a 5 1/4" drive and a 3.5" too? Opinions welcomed!

Thanks for the suggestions. So, I made sure the twist was not used. Still same thing. I downloaded the manual for the Shugart 400L and, if I am reading this correct, the jumpers should be set correctly for a single drive system and drive 1. So I believe "HL and "1" are closed (drive 1). 2,3,MX,4,MH are OPEN. When I attempt to test the drive, I hear the heads (or something) clamp down pretty hard. But no LED. Then error 16. If I CLOSE "MH", the same thing happens but this time, I get the LED coming on when it's performing a test. The drive has been properly cleaned and lubed. The only other drives I have are 1.2 MiB floppy drives which I'm pretty sure won't work. I have no idea if this drive actually works. Not sure how to test it other than maybe see if it works in my 486. Oh, here is the snippet of the manual:

I have a single 5 1/4" floppy (SA400L I believe). I also have the disk controller, obviously, in my PEB. When I try to run the Disk Manager (any version 1 - 3) and perform any tests, I get "DISK ERROR 16". Which I believe means no drive present. Now, when I power on the PEB, the drive LED comes on and makes a click...like the heads are clamping down. Then the LED goes off. I power on the TI and it does it again. On the disk drive end of the cable, I am using the old 5 1/4" connector. On the controller end, I am using the 34 pin "newer" connector. Sorry, I'm not sure what the actual names are. So the cable I have is 34 pin to TWO 5 1/4" connectors. One has a twist. I've tried both. Sorry, I'm running out the door but I can include pics, etc. later if needed. Just hoping someone knows of something stupid I am doing. Thanks for any suggestions.

I just bought a NanoPEB. I bought a 32K side car a few years ago and fried the RAM because (like a dummy), I didn't realize the card didn't have a 7805 or anything to regulate the voltage. Looks like the NanoPEB doesn't either. Which is a little disappointing. Shoot...I bet it wouldn't be too hard to remove the jack and put a tiny board in it's place with a properly regulated jack. Note to designers...please regulate your power! Sometimes we make a mistake and plug in 12V DC wall warts in these things without thinking! (yeah...shame on me but I did it)

Thanks to the both of you for some great suggestions. I probably didn't make much sense. I tend to get these ideas in my head and they kinda explode out into forum messages...I read them back and think..."what was I thinking??" lol OK, so the real point of the two goals was that I wanted a completely "vintage" TI setup with a PEB. Like we had back in the 80's. With the ability to print, play on BBS's, etc. Also, to load/save stuff to actual disks. I believe I mostly have that now. The only exception is the newer SAM memory card that is 1 MiB. I would love the get the 32K version that was released in the 80's but that doesn't make practical sense because I have the newer card. Still, I'd like to have it. But at $80 for one...I'll pass for now. So that's my vintage setup....the setup I bring out time to time and pretend it's 1982. Then there's the "every day" TI. The TI I will actually use most of the time. On this TI, printing is just a whim...I don't have to have that with my every day TI. BBS support would be nice. I already have that WiModem (or whatever it's called). I went ahead and bought the NanoPEB. This seemed to be more practical for my needs. It has a real serial port, emulates three floppies and has 32KiB. The TIPI just doesn't appeal to me. I know it's a great product. I already have several RPi's. Now, let the fun begin!

So substantially more than a "normal" home computer when you factor in inflation. ?

Interesting computer. I get annoyed sometimes when the point of articles (like the Wikipedia article) references how it did X "half a decade" before the Amiga. One thing that isn't mentioned is the price. This computer seems to use some custom ASIC's and up to 72KiB of RAM. What do you think that would have cost in 1980? ? Otherwise, I like the design. I love those "tank looking" computers.

Adrian's Digital Basement is a new favorite of mine. He goes into much more detail than the 8-Bit Guy. I just wished he would branch out to the TI's.

So, it's that time of year again when I can splurge a tad on myself. Some men my age buy a sports car. Some buy a boat. I want to buy some TI gear. ;-D Items I already own and use: FinalGROM 32K side-car FlashROM 99 F18A Speech Synthesizer I actually have a two-part goal. Goal One Fully load my PEB. I have the following already: RS-232 card (not tested) Disk controller and disk drive (not tested...hope to test this week) 1 MiB RAM expansion (tested...works...just need to put a heat-sink on 7805) Fire hose card/cable (tested...works) Possible additions: Quieter / slower fan Newer PSU (that transformer weighs about 750 lbs.) Ironically, I only want to use the PEB setup every now and then. That thing is a beast, weighs a ton and is loud as hell. But I love it. I want my "ever day" TI to be much slimmer. Which brings me to Goal Two Goal Two Streamline my basic TI-99/4A for general use and development. When not using PEB, I would like to be able to: Quickly load assembled programs from PC to test (i.e., I develop on PC and send file over to test) Get online (BBS mostly...not too interested in WWW) Use a printer (I have a few dot-matrix printers) Save data FROM the TI to "somewhere". I assume the Tipi would be for this? So I'm looking for suggestions on what to get for my goals. I'm also including books in this list. Basically anything for development is a plus. Also, I want to use more than just games. Gaming is great but I'm not looking for just a gaming console. Developing ON the TI would be a bonus. Thanks for any suggestions!

Thanks for the offer. I've bought from polida2008 before but have not tested the chips I got from him. However, I also found a 9902 from a US seller so I went ahead and bought it. Not sure if that makes much difference but he said he got them as new parts a long time ago. Thanks!

@FarmerPotato that's an excellent idea!! In fact, I know for a fact I have some legit SN76489's. Thanks for the suggestion. Keep in mind I have never programmed 99xx assembly so I may have more questions. ?

I'm thinking about wire-wrapping a small TMS9995 board and I have everything except a UART for it. It seems the TMS9902 is the preferred route. But all I have are some 65C51's and some modern NXP DUART's. Before I order a (possibly fake) TMS9902 off eBay...wait two months to arrive from China...discover they are fake....rinse/repeat, I was wondering: 1) Is there a somewhat reliable supplier of them in the US? I only need 1 or 2. 2) How difficult would using a non-standard TI part be? Something like the 65C51. 3) Something different? All I want to do is run a simple serial monitor and tinker around. Thanks for any suggestions.

I had a very similar experience. We had no money. I had a few carts but that's it. No PEB, disks, etc. So the vast majority of "new" software I had was typing from magazines and whatever my 9-12 year old mind could come up with. I remember I had a small box I kept by my desk for people to suggest the programs they wanted and I would write them!!! HAHAHA.

OK, my Atari 800 from cold boot...no carts....loads the notepad app. So from power up to typing would beat your TI because you have to load an app. Now, I would HARDLY call the notepad a word processor...so I guess you still win. LMAO!!

Holy crap I've been playing this game off and on for 38 years (literally my first computer game) and I never noticed that.

Oh wow. That's awesome! I will check that out later (can't FB at work). So I found a TMS9995ANL in my bin of CPU's. I have no idea if it's legit. I tried some IPA and hard scrubbing to see if anything came off (nothing did). So I thought I might try and wire-wrap a small prototype board. Unfortunately, I don't have any serial chips in the TMS family (9902 IIRC). So I may order one of those. The problem there is that there is no guarantee it will be legit either. Which sucks. I wonder how hard it would be to use a UART I'm more familiar with? Like a 65C51?

You guys are young whippersnappers. ? Being born in 1973, I was 9 when I got my first computer (the TI). So for me it went: TI-99/4A -> C64 -> Amiga 500 -> Amiga 1200 -> 386SX -> 486DX2/66 -> P133 -> Gateway 2000 (P3/450) -> (many many more...) The TI taught me so much. Being 9 years old (with no one else interested in computers), I struggled a bit when programming. The manuals with the TI are actually pretty good. As a kid, I had issues learning certain words (spelling) and I remember reading those manuals over and over and literally learning new words from those manuals. ?

I've been looking over the TMS9995 recently and was wondering if anyone is working on anything new with it?

Sorry to pimp out my own repo, but I've been collecting various documents centered around the TMS9918 chip and it's family. Which includes the SRAM replacement schematic. https://github.com/cbmeeks/TMS9918 If there is anything to add to it, I would be grateful. ?

This is exactly why I started this thread. I wish the guy lots of luck because we need quality retro-computer videos. But even the mighty 8-Bit Guy gets things wrong (and is biased). This guy is the same. You just have to take what he says with a grain of salt. But yeah...the TI unfairness was a little hard to stomach. He's also on the young side to be into retro computers. I always laugh when I hear "retro experts" talk about how a 486 was their first PC. They never had to live through the pain of saving/loading from tape. They never had to type in massive amounts of code on chicklet keyboards from magazines so that you had SOME software to use! (to be fair, I've never done punch cards) So their experiences are definitely different than mine. So when they see a "limited" computer like the TI, they often get things wrong.