emx wrote: Why do you need it? We found that our APL only machine included the BASIC implementation, we needed only to install the language selection switch on the front panel. I would be very interested in knowing if the same holds true for the BASIC only machine. -- HansP

On Tue, 6 Jul 2004, emx wrote: If you want to upgrade your BASIC only machine I have to tell you that it is not sufficient to replace the language card. AFAIK you will also need a new Executable ROS card because the APL interpreter "interpreter" is running from Exec ROS and fetching the opcodes of the APL interpreter from the Language ROS. BTW it's the same when trying to build a tape drive into a model 2 5110. This will require a new Exec ROS and a new Base I/O card. I don't know if adding backplane wires would be needed, too. But if you are just curious I can send you ROS images of the language ROS. Making an image from the Executable ROS is not trivial because the processor can't access this ROS during instruction execution phase, only during instructions fetches. This is the reason why loading word constants into registers in ROS code can only be done with LBI,MLH,LBI and not LWI (i.e. PC relative with postincrement). For example, to load the constant $A62F into R2 you have to write LBI R2, #$A6 MLH R2, R2 LBI R2, #$2F instead of LWI R2, #$A62F which means MOVE R2, (R0)+ DW $A62F <- this is a data word that can't be read from ROS Christian