Circuit Notes; Processor Card; Boot Rom, Flash, And Ram; Trim Procedure - Jands Event 4 Technical Manual

Circuit Notes

3. Circuit Notes
The Event 4 uses a main CPU to provide all processing functions. The CPU
communicates with the front panel PCBs via the front panel card bus.

3.1 Processor Card

The major functional blocks are as follows:
Core CPU
Boot EPROM
FLASH ROM
RAM Bank 1
Floppy Disk Drive Controller
DMX output
MIDI
VGA output
Reset/power fail/RAM power
Real time clock
Front Panel Card bus
Expansion bus

3.1.1 Boot ROM, FLASH, and RAM

The CPU memory consists of a Boot EPROM (IC25), four FLASH ROMs (IC11,
IC12, IC13, IC14), and four static RAMs (IC16-19).
The CPU card has the capacity to be fitted with a maximum of 2MBytes program
memory (four x 29F040 devices) and 2MBytes show memory (four x 512Kbyte
devices).
Only AMD brand 29F040 FLASH devices should be used with boot software versions
up to 0.5.

3.1.2 Trim procedure

The adjustment trim on the CPU card adjusts the point where the CPU is informed that
power is failing. If a console is dropping its memory, trimpot T1 may be out of
adjustment and should be adjusted as follows:
1. Save any necessary console information to diskette
2. Turn T1 fully anticlockwise
3. Place a shunt across J1
4. Switch console on and wait until it has completely started up
5. Slowly adjust T1 until LED L3 lights
Revision 1 - 07 July
1999
Function IC Number
IC1-8, IC33, IC30, OSC1
IC25
IC11-14
IC16-19
IC48
IC53, IC38, IC39, IC50, IC51
IC48, IC35, IC52
IC6, IC57-60, IC66
IC15
IC31
IC9, IC10
IC24, IC26-29
Event 4
3 - 1
TECHNICAL MANUAL