LanGuardian - Miscellaneous Information

EPROM chip information

The LanGuardian has two EPROM chips in it, both 64K x 16 bits. These make up the high and low banks of ROM memory. When they are accessed, they are accessed together. Thus, all ROM accesses happen at full bus speed, 32 bits at a time.

DRAM SIMM information

The LanGuardian has two SIMM slots in it. The LanGuardian support 4BM, 8MB, 16MB and 32MB SIMMs. If two SIMMs are in the machine, they MUST be the same size. The DRAM should have the following characteristics: 36bit (i.e. ECC), 60ns, fast page mode, 72 pin SIMMs.

PDE menu choices

Use a 'space' character to walk through choices in menu items (eg: memory type, TFTP/BOOTP).

EPROM chips

The EPROM chips that are in a LanGuardian are 27C210A-15 EPROMs, which are 150 nanosecond, 1 Mbit devices.

Register contents initialized by the PDE when a program is booted

envp->regs.PC = start_pc;
envp->regs.Aregs[7] = USER_STACK = memory_size;
envp->regs.Dregs[3] = devtype;
envp->regs.Dregs[4] = howto;
envp->regs.Dregs[5] = segsize;
envp->regs.Dregs[6] = memmap;
envp->regs.Dregs[7] = memory_size;

Comments or Questions? send email to : languard (at) pix (dot) net