Blogs

 

All members are invited to blog on Applefritter. Weblogs should generally be of a technical nature and should be written in such a way as to still be readable and useful 50 years from now. Please do not embed outside media. Images and videos can be uploaded via the Media Browser. Files should either be attached to the blog post or uploaded to the file libraries.

 

When you post to your blog it will appear on this index and on your personal blog page. Once you've made a few posts, contact me about having a graphic added on the top of this page.


A Quick Way To Solve Your Problem For Loans

1. A loan can Commute the interest Paid on existing debts.

Almost there!

I replaced the HAL with a GAL I programmed and it made absolutely no difference.  That lead me to suspect he MMU (344-0010-B) of being fauklty and I was able to get hold of a replacement MMU temporarily.  I swapped the MMU over and it sprang to life!  The only remaining fault is thet the keyboard input is garbled, however as I have not replaced he Keyboard ROM and the original gets pretty hot, I think I can guess what the problem is.  My attention now is on how to replave the MMU.

Getting warm, in more ways than one

So in my last entry I mentioned that the ICs LS245, 341-0170-A, 74166, 6502 and 341-0150 were getting warm.  This wasnt the full list, the MMU, IOU and ROMs were also feeling a bit above room temperature, but it was subtle.  After looking at the schematic however, I think I now have a pretty good idea of what's going on.  The LS 245 is getting very hot.  It is an octal bus trancever that connects 74166 to the databus, based on it's inputs from the HAL and the MMU.  The 74166 is also getting very hot and it is controlled by the MMU and the IOU.  The ROMs and the CPU are getting hot because t

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