Text not appearing correctly Apple IIe

Well, a few things.. check that the chip numbers and speeds are correct, like the video & character generator rom. Check that all the pins on the chips are spit polished silver. Move some ram around and see if the problem changes. Get the basics done first, then we can get down to business.

These days when I get some classic hardware I'm always prepared to buy two or three of the same item for spare parts. Between them I'm always able to get a 100% working unit going.

The dark vertical lines indicate a bad RAM-Chip and the position of the vertical line indicates which one...:
If you look close to a letter with a thought horizontal line in the letters that are display in text mode by :
Bit 7 , 6 , 5 , 4 , 3 , 2 , 1 , 0 ...... and that again indicates the chip that should be swapped....
up to my guess its chip 0 or chip 7 at one of the ends of the row.... if they are in socket the cause might be a misfitting in the socket...

and the mixing between US character and German character seems to indicate that that char-gen chip is not proper in the socket or there is trouble with the switch ( if there is on in ... ) if no switch is in - the one pin of the char Gen is not proper in the socket or the Char Gen is damaged...

I think RAM for bit 1 and 4 have gone bad. Your unit is probably unenhanced, and it was trying to display KERNEL OK when you did the three fingers solute.

I still remain by the point that at least one RAM is bad.... The chip is a 4164 dynamic RAM and was most common in those days... if you have any RAM cards in the shelf for example a 80 colomn 64 kbRAM card that is equipped too with 4164 RAM chips. Also some old RAM cards for the APPLE II have that chip like the common 128 KB Cards ( f.E. Saturn ) and fastest way to determin the bad chips is by swapping in the order : 4 chips swapped -> 2 chips swapped -> 1 chip swapped
which will always turn out with the fault chip by remaining to the question : yes or no - and that answers the question: was the faulty chip just now swapped or not... if not the faulty chip is still in the not-swapped portion - if yes the chip is within that portion that just was swapped .... so after 4 swaps the faulty chip should remain in your hand....

and the problem with the char gen is related to the second picture from Top:
in correct operation either APPLE ][ or APPLE ÜÄ should be displayed.... but not ASPPLE ÜY .... there is one reason : a faulty chargen or at least a faulty mapping ( 1 adrees-line going wrong ) or it gets wrong signal from the switch that shall switch between both character sets by switching the highest adress-line...

The chips have a printing at top that display typ and timing
for example 4164-2 is a 4164 chip with timing of 200 nanoseconds
4164-3 has a timing of 300 nanoseconds -i.e. is "slower"
and 4164-15 has a timing of 150 nanoseconds - i.e. is very fast....
the rule is: the faster the better...
swapping is not dependent to the order...
but up to my guess - i would startup with the 2 left and right outside...
and thereafter swap single chips back...
if swapping back chip again turns up with mistake then one chip is detected to be bad....
and marked ...
after each check of the chips ( by loading the game - vertical stripes indicate mistake ) proceed to next step

If character hazzle continues and RAM chips can´t be located it would indicate the problem not to be related to the RAM or character ROM itself but rather more to the chips responsible for the adressing... if this turns up give here notice and i will explain next steps to identify problem closer...

first hint in that case would be to checkout that 40-pin chip, that is marked at the mainboard ( white printing ) as "MMU" ( shortage for: Memory Managment Unit ).... check carefully that all pins are straight and correct in the socket... in most cases one pin is bent and slipped down under the chip and not in the socket... in the picture above its the one above the auxiliary slot...

Hello, so now the options are getting rare.... i have roughly examined the circuitplans of the IIe and there are only three chips remaining on the board that can be replaced without pain and that are in relation to the adressing and data bus: there are 2 chips marked 74LS244 and one chip marked 74 LS125.... the LS125 is responsible for mapping blocks of memory and i therefor guess its not the problem because a malfunction of that chip would also cause other effects too... so at the end there might only be the chance with the 2 74LS244 chips that have contact with the Adressing and Databus and a malfunction could affect the computer in the same way ( and i asume that you of course have allready checked the correct position of the CPU itself....
so if a change of those 2 chips does not solve the problem then the malfunction is for sure caused by the MMU-chip itself and that will be a big problem, because that chip is a custom chip manufactured only for apple itself and there is not the slightest chance to get it in a normal electronic shop ..... the only chance to get that chip is to pull it from another mainboard or to get it from somebody who has access to former apple-service-units as original Apple sparepart.... and if you change that chip you must keep sure its from same kind of board.... taking a chip from a NTSC-Board ( for US-Market ) and pluging it in a PAL-Board that was determined for european market will just cause more trouble.... because the timing in the two boards have differences and due to the close interaction between the MMU and the IOU chip - trouble is forecasted ahead if you don´t make sure to get the correct MMU... In this worst case scenario of damage the board will only remain as sparepart holder.... just one final rescue idea would be - to really examine roughly the slots with a magnifying glass and look precisely if there is any shortcut at the contacts or at the very bottom of the slot....
good luck...

Hello,
the problems that you face may be splitted in two tasks:
the vertical dark lines in graphic mode are a result from the fact that one or two bits of the RAM drop and therefor in the video-pages the display shows up nothing ( is blank and keeps dark ) ....

the location of the dark lines indicate which of the Bit / Bits is / are not present....
each letter displayed in text-mode is represented by 8 lines of bits....
due to the fact that in the picture the letters seem to be correct, the bits that might be affected therefor must be the first or the last bit ( which remains as spacing between the letters )- but shows up in graphic-mode as blank vertical line.....

that results from one of the following mistakes ( in the order of how often they occur from often -> rare):
misfitting in socket, damaged due to static electrical shock, shortcut at the databus at a specific bit-line,
malfunction of a databus related chip.....

the second problem ( displaying wrong characters ) results from wrong-adressing of the char-gen-chip....
or the char-gen-chip to be wrong version...
( if it is related to only bits it only shows up in display )
if it is related to adress-mapping it also shows up by typing )

if it is regular it is related to a fixed-malfunction of an adressing line or the char-gen-chip -
if it only occurs randomly it is related to the keyboard or the timing on the adressing bus....
if the malfunctioning Characters are changing its more related to timing
if the wrong characters are allways the same its related to the wrong char-gen-chip
or the wrong mapping of the char-gen-chip.

To understand the Apple it is important to understand that the Memory is splitted in blocks
and the decoding of which block of memory is active used is the job of the 74LS125
which also decides if the use of the Memory or the ROMs or the Slots are used.

The 74LS244 are responsible to switch and buffer the adressing-lines.
They operate as temporal storage ( for very short period ) for the demanded adress
and they decide if the adress is coming from the CPU or from a SLOT or from one of the custom-chips ( IOU or MMU ).
The 74LS244 may also be replaced for testing puposes with the 74ALS244, the 54HC244 ( the chip for military purposes ), the 74F244 ( for very fast applications ) and the 74S244 ( also for fast applications ). They are all pin-compatibel (i.e. the outline of the pins are the same )

the good news is that these chips are very common and you can get them at every electronic supplier like radio shack, tandy or in Germany Conrad electronics or similar or in a computer repair shop just out of the stock.....
and they are found on nearly every second or third old interface card or just even also an modern computer cards
- the problem on modern cards: the chips used common there are the very tiny SMD-versions, which dont fit in a socket but are soldered to the board...

For the correct IOU versions and MMU i will reply soon after i checked out in my archiv... same is valid to the video chip too...
regards...

Hello robbo007,

As a French guy, I can told you the problem was solved by replacing the Video ROM chip (341-016x).

the ROMS can be replaced simply with a 2764 EPROM. The files for those EPROMS are availiable in Internet at several sources. You just need somebody to program the EPROMs....
and as I explained in the last posting i will send a list of permitted combinations and the adresses for the files needed to burn the EPROMS. that post will come when i finished my other tasks today because i first have to finish those things that are limited by "deadlines" like they are set from court to pass over a statement ... that has for sure priority and has to be finished first ! Then i will search my archive as explained... O.K. ?

so in the meantime i finished my other tasks....

as explained here a kind of reference list of the ROMs and others:

First the correct numbers for the German custom chips:
IOU => 343-0022
MMU => 343-0010

and now the ROMs.....
be careful and note:
ROMs without country code are used in both languages !
Those ROMs that are specific to languages are indicated by country codes
US => USA
UK => United Kingdom
DE => Germany

the the correct file-combination for the IIe enhanced are:
Apple IIe CD Enhanced - 342-0304-A - 2764.bin
and
Apple IIe EF Enhanced - 342-0303-A - 2764.bin

Apple IIe Video Enhanced - US Version - 342-0265-A - 2732.bin
or
Apple IIe Video Enhanced - US -UK - 342-0273-A - 2764.bin
or
Apple IIe Video Enhanced - US-DE - 342-0275-A - 2764.bin

the the correct file-combination for the IIe not enhanced are:
Apple IIe CD Unenhanced - 342-0135-B - 2764.bin
and
Apple IIe EF Unenhanced - 342-0134-A - 2764.bin

Apple IIe Video Unenhanced - 342-0133-A - 2732.bin
or
Apple IIe Video Euro Unenhanced - USA - UK - 341-0160-A - 2764.bin
or
Apple IIe Video Euro Unenhanced - USA - DE - 341-0161-A - 2764.bin

those marked with 2732 are old ROMs that might be replaced with 2732 EPROMs and contain less code

the keyboard ROMs might be replaced by 2716 EPROMs.
Apple IIe Keyboard - US - UK Version - 341-0150-A - 2716.bin
Apple IIe Keyboard - US - DE - 341-0151-A - 2716.bin

The coding for the correct EPROM-typ ( i.e. 2764, 2732, 2716 ) were added by me later in the archive to indicate correct EPROM-typ....
In the internet the files probably don´t have that in their names - but the only important part in that filenames are the "apple-codes" ( i.e. 342-0XXX )

the sources for download of the related files is:
http://mirrors.apple2.org.za/Apple%20II%20Documentation%20Project/Computers/Apple%20II/Apple%20IIe/ROM%20Images/

so if you have a friend who is capable of programming EPROMs he might help you to make the fitting EPROMs.
at least you have the possibility to checkout if you have the correct chips in....

it is not permitted to mix unenhanced chips with enhanced chips
and it is not permitted to mix US-only or US-UK versions with US-DE versions.

and one remark to amauget...
your point only probably solves the wrong display of the characters... it does not solve the dark-lines in the graphics page !
regards

Wrong....

the dark lines are not solved and problem is dependent to the MMU ..... other reasons have been proved not to be responsible....

second the wrong characters are probably related to VIDEO ROM and that is 2764 EPROM and they are in the list as VIDEO ROM.
The Character ROM might be a Problem but that is not sure at the moment.
First of all check that ROMs are not from different Versions
( i.e. enhanced are not mixed with unenhanced
and
that not US-Versions are mixed with German versions).
Please re-read very carefull again...
and check that the IOU has correct Apple ID Number because that is dependent to NTSC or PAL version !

That looks correct for a IIe in the unenhanced version with US-DE ROMs.
The IOU and the MMU are the correct versions for the european IIe in the PAL-version.
The CD-ROM and the EF-Rom are the correct versions for the unenhanced IIe and these ROMs are not language specific.
The Video-ROM and the Character ROM are the correct ones for the unenhanced for the German Market ( they are language specific and both have the German Character-set in side as US - DE because both contain the DE in their coding - so thats correct.

This brings us up back to the point that i explained- that either the MMU or the IOU has malfunction and my first try would be to change the MMU ( if you get one with the same codes as explained above and certified by you ). The second try would be to swap the IOU.
The mixing of A and B Version chips is up to my knowledge rather normal within the minor revisions within an entire series and should not take that effect to cause such malfunctions like in this computer. The real important is the code number - because if changes were made to an entire series ( like upgrade from unenhanced to enhanced ) the codenumbers themselves were changed....

The MMU and the IOU are CUSTOM-CHIPS ! They can´t be replaced with EPROMs !
This was explained in my previous posting #13 !
the possibility to replace is only given for the ROMs and not for the custom Chip´s !
this is also the reason that in my listing behind the coding NO EPROM TYP was added !

I wonder if we are not looking at a 16R8 HAL issue or its connections to the IOU, not to mention the IOU itself.

An easy test could be swapping the LS374 video latch too.

If the Hal would be the problem, the mistake would display in another form: there would be trouble with the colorsignal ( see reply #6 ) in the graphic pages displayed in the pictures above.... i asume that you have taken a close look to those pictures ... did you ? and if the IOU would be the cause of the trouble the mistake would also differ from the stated and examined points... several tests have been solved already in earlier posts.... have you read the entire thread ?