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Stewart Conner's 99110 Project


dhe

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Just a few questions for anyone that has worked through this board.
 
   Has anyone created a digikey BOM?
 
    Is there a preferred or non-preferred vendor for 99110/99105's - as they are all pretty much $35 from China.... I'm guessing some type of pulls.
 
    Can someone point me to a power supply?
 
    Anyone put in ZIF sockets?
 
    Anyone that has built this, any tips to share?
 
Thanks,
Dano
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Exciting!

 

I'm studying Stuart's board very closely for my own version, adding 9901 and V9958. (not sure if the 9901 is going to work.)

 

I got the 99105 from polida2008 on eBay for $33. You can ask him or hth-chips (also eBay) to make a custom eBay listing for you with all the chips you want.    I have not verified the 99105 running code yet, only that it powers on and clocks.

 

You can also get 32-pin ZIF for the ROMs on eBay. I ordered those and a bulk lot lot of crystals and discrete components from giorgio11185 (eBay). Happy to share those.

 

The narrow RAMs are nice, but I'm using plain old wide ones.

 

My power supply is a bench supply. If you use an AC adaptor, (or any supply) you should check the voltage rail with a scope. When I first put the 99105 in, it was swinging from 4.75 to 5.25 with the clock pulses, barely in spec. Caps tightened that up.

 

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3 hours ago, dhe said:
Just a few questions for anyone that has worked through this board.
 
   Has anyone created a digikey BOM?
 
    Is there a preferred or non-preferred vendor for 99110/99105's - as they are all pretty much $35 from China.... I'm guessing some type of pulls.
 
    Can someone point me to a power supply?
 
    Anyone put in ZIF sockets?
 
    Anyone that has built this, any tips to share?
 
Thanks,
Dano

Has someone actually produced the 99110?  I haven't seen any on the market, just 99105s.  The '110 has the math routines in it, correct?

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Me and pnr had a few threads a couple of years ago talking about TMS99105 and TMS99110. If I recall properly we did also talk about sourcing TMS99110 chips. One of the interesting results was that some  TMS99105 chips actually turned out to be TMS99110 chips, i.e. they had the floating point macrostore ROMs. I haven't played around with my TMS99105 chips for a while, but I think I have three of them and one is actually a TMS99110.

 

You may already know, but I built a TI-99/4A clone using a TMS99105 and a FPGA chip: My TMS99105 project on hackaday.io

 

Here are the links to threads on this forum:

TMS99110 ROM disassembly discussion

Musings on 99000 macro code

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16 hours ago, dhe said:
Just a few questions for anyone that has worked through this board.
    Can someone point me to a power supply?
 
 

 

I'm getting one of these 25W CUI adaptors for $19. It has a 2.5mm barrel plug. 

 

https://www.mouser.com/ProductDetail/490-SDI36-5-U-P6

It's way overkill, but I plan to add a lot of other things for a budget of up to 12W.

 

 

 

I remember finding a 5V switching power supply in TI's dumpster, long ago, that powered my first 9995 project.

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I bought 2 ZIF 32-pin sockets from Polida2008 (eBay). I let my kids play with them first, cuz they are the neatest connectors around. After loading a chip in and out a few times on one, they tried the other! It wouldn't go in!

 

Looks like I got wonky ZIFs. One of them locks with the lever down. The other locks with the lever up. Is this a normal variety?

 

They say 3M on them, but I have a doubt.

 

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  • 2 weeks later...

Hi,

 I've been working with Newark, as they seem to have better access to European parts. Can those with a better grasp of electronics give me their opinion on this BOM ( I'm more of build a basic Heathkit by the numbers kind of guy! =0 )

Thanks,

Dan

 

 

Circuit Diagram Reference Description Source Approx. Cost
(excl. delivery)
Newark Part Number Cost Per
- For the breadboard system, 3 pieces of solderless breadboard, each section approx. 175 × 65 mm (64 contact points (holes) long by 10 wide, 2 pairs of bus strips along each edge of the board, see this photo) eBay £10 for the 3 sections 50AC8943 7.75
- For the PCB version, contact me for availability of a PCB - -   N/A
U1 TMS 99110A microprocessor
(a TMS 99105A is normally easier to obtain)
eBay £30 (I got a working TMS 99105A from eBay seller "polida2008")   N/A
U2, U3 74ALS573 (BN or CN suffix OK) octal D-type transparent latch IC eBay £4 each 60K6796 1.38
U4, U5 74ALS645 (AN or A-1N suffix OK) octal bus transceiver IC eBay £2 each 08F6096 0.38
U6 74LS32 quad 2 input OR gate IC eBay £1 67K2856 0.66
U7 74LS04 hex inverter IC eBay £1 33AH4881 0.79
U8, U9 32K byte 27256 or 27C256 EPROM, 120ns or faster (ST part # M27C256B-12XF1 works) eBay £2 each 05W3274 N/A
U10, U11 32K byte 62256 static RAM, 85ns or faster, 'skinny' 0.3" wide package(Winbond part # W24257AK-20 or UMC part # UM61256K-15 work) eBay £2 each  
Available with Board Order from SC
U12 74LS138 3-to-8 line decoder IC eBay £1 60K6860 0.84
U13 TMS 9902ANL asynchronous communications controller (ought to be the TMS 9902ANL-40 variant to work at 4 MHz, but a standard version seems to work OK) eBay £10 (ignore the overpriced ones at £140!)   N/A
U14 MAX232CPE+ dual RS-232 transceiver eBay £2 81Y9311 3.65
X1 16 MHz crystal (AEL Crystals part # X16M000000L259 should work) eBay £4 98K3449 0.97
C1, C2 5pF (or 4.7pF) ceramic capacitor Maplin ‑ part # WX40T £0.20 for the 2 Voltage rating Req. 13K6284 ? 0.32
C3, C5 - C10, C12 - C17 0.1μF ceramic decoupling capacitor Maplin ‑ part # BX03D £1.30 for the 13 37K7184 1.87
C4 4.7μF tantalum capacitor, 16V Maplin ‑ part # WW64U £0.30 25M8466 0.02
C11 22μF electrolytic capacitor, 16V Maplin ‑ part # KQ65V £0.30 70K9672 0.02
C18 - C22 1μF electrolytic capacitor, 16V Maplin ‑ part # AU09K £1.75 for the 5 13M5148 0.02
R1 - R6 10K metal film 0.6W resistor Maplin ‑ part # M10K £0.60 for the 6 26R4084 0.04
R7 220 Ohm metal film 0.6W resistor Maplin ‑ part # M220R £0.10 45X4683 0.07
D1 LED, 3mm, red Maplin ‑ part # UK18U £0.20 16M1519 0.69
SW1 Single pole, push-to-make, PCB mount, non locking switch Maplin ‑ part # KR91Y £1.50  
Available with Board Order from SC
J1 DC power socket (female), 5.5 × 2.1mm, PCB mount if building on the PCB eBay £1 94X0662
Available with Board Order from SC
J2 9-way D-type socket (female), PCB mount if building on the PCB eBay £2 42K6561 5.59
- IC sockets (machine screw) if building on the PCB (all 0.1" pin spacing):
• 1 × 40 pin
• 4 × 28 pin, 0.6" wide
• 2 × 28 pin, 0.3" wide
• 4 × 20 pin
• 1 × 18 pin
• 2 × 16 pin
• 2 × 14 pin
    Need Pin Spacing  
           
           
  • 1 × 40 pin     52K3717 3.98
  • 4 × 28 pin, 0.6" wide     17C2341 4.21
  • 2 × 28 pin, 0.3" wide     04M0623 1.45
  • 4 × 20 pin     98K7085 0.98
  • 1 × 18 pin     98K7083 0.83
  • 2 × 16 pin     98K7081 0.75
  • 2 × 14 pin     82K7800 2.77
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 The 14 pin sockets seem pricey, but you can take 16 pin and snip off one row. I would not get machine pin sockets. They are harder to use, and according to some they are electrically inferior to double-wipe (the other kind.)

 

For the discretes, like 0.1 uF and the resistors, order lots of extra. You will drop some, or use them in all future projects. 

 

On the 74ALS573 and 74ALS645, you have the ALS variety - good. You need the fastest response in those parts (faster than LS).

 

The 9902s can be had on eBay for as little as $2 each. The memories are cheap there too. You can get all of these from polida2008 or hth-chips on eBay. If they're not listed separately, just ask and he will make a kit for you. The 99105 should be $33 from these sellers.

 

For the crystals, I'm stocking 12,16, and 24 MHz, but I think 16 is what the ROM for the 9902 assumes.

 

 

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