I'm attempting to restore an Imsai front panel (FP) handed down to me by my 
Father. I've used the chassis back in the day with a reset switch wired to 
a proto board with mostly CompuPro hardware. I believe Dad had the FP 
working with a Tarbell controller. Now I've dug out the front panel and 
would like to restore it and the entire Imsai 8080 to functionality. I 
believe I have the original Imsai boards. I've already rebuilt 
<http://www.rodaw.com/imsai-power-supply-rebuild/>the power supply. And 
have one of Josh's 8080 cpu boards running in it. So reset and run work! I 
also have an Imsai front panel simulator 
<http://www.autometer.de/unix4fun/z80pack/index.html> running in a VM to 
remind me of front panel operation.

I have the original Imsai documentation. I scanned the FP parts list and 
OCRed it into a spread sheet. 

  8T97 1 Hex Tri-State Buffer/N8T97B   7400 2 Quad 2 Input NAND/SN7400N   
7402 2 Quad 2 Input NOR/SN7402N   7404 1 Hex Inverter/SN7404N   74LS04  2 Hex 
Inverter (Low Power Schottky)/SN74LS04N   7405 5 Hex Inverter Open 
Collector/SN7405N   7410 1 Triple 3 Input NAND/SN7410N   74LSI0  1 Triple 3 
Input NAND (LPS}/SN74LSION   7427 1 Triple .3 Input NOR/SN7427N   7430 1 8 
Input NAND/SN7430N   74LS30  1 8 Input NAND (LPS)/SN74LS30N   7805 1 SV 
Positive Volt Regulator/MC7805CP   8212 1 I/O Port/P8212/S1002   74107 3 Dual 
J-K Flip Flop With Clear/SN74l07N   74123 3 Dual Monostable Multivibrator, 
Retriggerable with Clear/SN74123N     

I thought I would lay in a set of spare parts before I begin. I can get 
most of the parts at Jameco less expensively than DigiKey, however DigiKey 
has specific versions of parts that Jameco does not. The N8T97B I found at 
Wholesale 
Electronics, Inc <http://www.weisd.com/>. crossing to a NTE6887 
<http://www.weisd.com/test/WEISD_TBL_view.php?editid1=NTE6887>Didn't see it 
at JameCo or DigiKey. FWIW I've attached a Jameco cart as 
jamecoImsaiFpList.csv

I'm inclined to repair the board with available parts but am thinking a bit 
about whether I should restore it with all original parts. Would that be 
better for a donation to a university or museum or just preservation of 
historically significant hardware?

What substitutions can be made for 7404/74LS04. Will the LS version be 
suitable for both parts? The parts list also calls for separate 7410 and 
74LS10, as well as separate 7430 and 74LS30. 

Although reset and run work, it looks like examine and deposit circuits are 
having difficulty. With all switches down I don't appear to be able to 
deposit to zero, nor examine. the [deposit | examine] next seem a bit flaky 
but may be due to the [examine|deposit] not working correctly.  So far I've 
tested all the switches. I had to open one up and clean the contacts. It 
appears to be working now. I replaced a couple LEDs, bummer that they are a 
bit more clear and consequently brighter but not extremely noticeable with 
plastic FP installed. 

I've read the CP-A rev. 4 construction and operation portions in the 
documentation. I found these threads 
http://fixunix.com/cp-m/50-imsai-troubleshooting-hints-faqs-etc.html 
and http://ana-3.lcs.mit.edu/~jnc/cctalk/2001-September/1400.html with some 
tidbits. Anyone know of other resources I might want to review?

Some help nailing down a parts list would be appreicated.

Thanks! - jeffa



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Jameco Shopping List "Imsai Front Panel"
www.Jameco.com
1-800-831-4242
Export Date,02/25/2015


Jameco Part Number, Description, Manufacturer, Manufacturer Number, Quantity, Unit Cost, Link
46404,"IC,74LS10N,DIP-14,TRIPL 3INPUT","MAJOR BRANDS","74LS10","2.0","$0.59","http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&productId=46404&langId=-1";
49040,"IC,7404N,DIP-14,HEX INVERTER","MAJOR BRANDS","7404","1.0","$1.59","http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&productId=49040&langId=-1";
49074,"IC,7405N,DIP-14,HEX INVERTER","MAJOR BRANDS","7405","1.0","$1.29","http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&productId=49074&langId=-1";
49189,"IC,7410N,DIP-14,TRIPLE 3-INPUT","MAJOR BRANDS","7410","1.0","$1.49","http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&productId=49189&langId=-1";
49234,"IC,74107N,DIP-14,DUAL J-K","MAJOR BRANDS","74107","1.0","$1.19","http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&productId=49234&langId=-1";
49357,"IC,74123N,DIP-16,DUAL MONOSTBL","MAJOR BRANDS","74123","1.0","$3.95","http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&productId=49357&langId=-1";
50139,"IC,7427N,DIP-14,TRIPLE 3-INPUT","MAJOR BRANDS","7427","2.0","$0.99","http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&productId=50139&langId=-1";
50227,"IC,7430N,DIP-14,8-INPUT","MAJOR BRANDS                            ","7430                                    ","2.0","$0.69","http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&productId=50227&langId=-1";
52468,"IC,8212 (74S412),I/O PORT","MAJOR BRANDS","8212","1.0","$4.95","http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&productId=52468&langId=-1";
283792,"IC,SN74LS04N,DIP-14,","TEXAS INSTRUMENTS","SN74LS04N","1.0","$0.55","http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&productId=283792&langId=-1";
830047,"IC,SN7402N,QUAD 2-INPUT NOR GA","TEXAS INSTRUMENTS","SN7402N","1.0","$2.05","http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&productId=830047&langId=-1";
910901,"IC,SN7400N,DIP-14,QUAD 2-INPUT","TEXAS INSTRUMENTS","SN7400N","1.0","$1.45","http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=10001&productId=910901&langId=-1";



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