diff --git a/.travis.yml b/.travis.yml
index 154f067e..87ffcab3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,7 +9,7 @@ env:
   - SIM="microvax2 vax730 vax750 vax780 vax8200 vax8600 microvax2000 infoserver100 infoserver150vxt microvax3100 microvax3100e vaxstation3100m30 vaxstation3100m38 vaxstation3100m76 vaxstation4000m60"
   - SIM="microvax3100m80 vaxstation4000vlc infoserver1000 nova eclipse hp2100 hp3000 i1401 i1620 s3 altair altairz80 gri i7094 ibm1130"
   - SIM="id16 id32 sds lgp h316 cdc1700 swtp6800mp-a swtp6800mp-a2 tx-0 ssem b5500 isys8010 isys8020 isys8030 isys8024"
-  - SIM="imds-210 imds-220 imds-225 imds-230 imds-800 imds-810"
+  - SIM="besm6 imds-210 imds-220 imds-225 imds-230 imds-800 imds-810"
   - SIM="scelbi 3b2 i701 i704 i7010 i7070 i7080 i7090 sigma uc15"
 sudo: required
 install: sh -ex .travis/deps.sh
diff --git a/makefile b/makefile
index 6c9bf173..cc39d0e5 100644
--- a/makefile
+++ b/makefile
@@ -1250,18 +1250,21 @@ LDFLAGS := $(OS_LDFLAGS) $(NETWORK_LDFLAGS) $(LDFLAGS_O)
 # Common Libraries
 #
 BIN = BIN/
-SIM = scp.c sim_console.c sim_fio.c sim_timer.c sim_sock.c \
-	sim_tmxr.c sim_ether.c sim_tape.c sim_disk.c sim_serial.c \
-	sim_video.c sim_imd.c sim_card.c
+SIMHD = .
+SIM = ${SIMHD}/scp.c ${SIMHD}/sim_console.c ${SIMHD}/sim_fio.c \
+	${SIMHD}/sim_timer.c ${SIMHD}/sim_sock.c ${SIMHD}/sim_tmxr.c \
+	${SIMHD}/sim_ether.c ${SIMHD}/sim_tape.c ${SIMHD}/sim_disk.c \
+	${SIMHD}/sim_serial.c ${SIMHD}/sim_video.c ${SIMHD}/sim_imd.c \
+	${SIMHD}/sim_card.c
 
-DISPLAYD = display
+DISPLAYD = ${SIMHD}/display
 
-SCSI = sim_scsi.c
+SCSI = ${SIMHD}/sim_scsi.c
 
 #
 # Emulator source files and compile time options
 #
-PDP1D = PDP1
+PDP1D = ${SIMHD}/PDP1
 ifneq (,$(DISPLAY_OPT))
   PDP1_DISPLAY_OPT = -DDISPLAY_TYPE=DIS_TYPE30 -DPIX_SCALE=RES_HALF
 endif
@@ -1271,7 +1274,7 @@ PDP1 = ${PDP1D}/pdp1_lp.c ${PDP1D}/pdp1_cpu.c ${PDP1D}/pdp1_stddev.c \
 PDP1_OPT = -I ${PDP1D} $(DISPLAY_OPT) $(PDP1_DISPLAY_OPT)
 
 
-NOVAD = NOVA
+NOVAD = ${SIMHD}/NOVA
 NOVA = ${NOVAD}/nova_sys.c ${NOVAD}/nova_cpu.c ${NOVAD}/nova_dkp.c \
 	${NOVAD}/nova_dsk.c ${NOVAD}/nova_lp.c ${NOVAD}/nova_mta.c \
 	${NOVAD}/nova_plt.c ${NOVAD}/nova_pt.c ${NOVAD}/nova_clk.c \
@@ -1286,7 +1289,7 @@ ECLIPSE = ${NOVAD}/eclipse_cpu.c ${NOVAD}/eclipse_tt.c ${NOVAD}/nova_sys.c \
 ECLIPSE_OPT = -I ${NOVAD} -DECLIPSE
 
 
-PDP18BD = PDP18B
+PDP18BD = ${SIMHD}/PDP18B
 PDP18B = ${PDP18BD}/pdp18b_dt.c ${PDP18BD}/pdp18b_drm.c ${PDP18BD}/pdp18b_cpu.c \
 	${PDP18BD}/pdp18b_lp.c ${PDP18BD}/pdp18b_mt.c ${PDP18BD}/pdp18b_rf.c \
 	${PDP18BD}/pdp18b_rp.c ${PDP18BD}/pdp18b_stddev.c ${PDP18BD}/pdp18b_sys.c \
@@ -1303,7 +1306,7 @@ PDP9_OPT = -DPDP9 -I ${PDP18BD}
 PDP15_OPT = -DPDP15 -I ${PDP18BD}
 
 
-PDP11D = PDP11
+PDP11D = ${SIMHD}/PDP11
 PDP11 = ${PDP11D}/pdp11_fp.c ${PDP11D}/pdp11_cpu.c ${PDP11D}/pdp11_dz.c \
 	${PDP11D}/pdp11_cis.c ${PDP11D}/pdp11_lp.c ${PDP11D}/pdp11_rk.c \
 	${PDP11D}/pdp11_rl.c ${PDP11D}/pdp11_rp.c ${PDP11D}/pdp11_rx.c \
@@ -1323,7 +1326,7 @@ PDP11 = ${PDP11D}/pdp11_fp.c ${PDP11D}/pdp11_cpu.c ${PDP11D}/pdp11_dz.c \
 PDP11_OPT = -DVM_PDP11 -I ${PDP11D} ${NETWORK_OPT} $(DISPLAY_OPT)
 
 
-UC15D = PDP11
+UC15D = ${SIMHD}/PDP11
 UC15 = ${UC15D}/pdp11_cis.c ${UC15D}/pdp11_cpu.c \
 	${UC15D}/pdp11_cpumod.c ${UC15D}/pdp11_cr.c \
 	${UC15D}/pdp11_fp.c ${UC15D}/pdp11_io.c \
@@ -1334,7 +1337,7 @@ UC15 = ${UC15D}/pdp11_cis.c ${UC15D}/pdp11_cpu.c \
 UC15_OPT = -DVM_PDP11 -DUC15 -I ${UC15D} -I ${PDP18BD}
 
 
-VAXD = VAX
+VAXD = ${SIMHD}/VAX
 VAX = ${VAXD}/vax_cpu.c ${VAXD}/vax_cpu1.c ${VAXD}/vax_fpa.c ${VAXD}/vax_io.c \
 	${VAXD}/vax_cis.c ${VAXD}/vax_octa.c  ${VAXD}/vax_cmode.c \
 	${VAXD}/vax_mmu.c ${VAXD}/vax_stddev.c ${VAXD}/vax_sysdev.c \
@@ -1512,7 +1515,7 @@ VAX8600 = ${VAXD}/vax_cpu.c ${VAXD}/vax_cpu1.c ${VAXD}/vax_fpa.c \
 VAX8600_OPT = -DVM_VAX -DVAX_860 -DUSE_INT64 -DUSE_ADDR64 -I VAX -I ${PDP11D} ${NETWORK_OPT}
 
 
-PDP10D = PDP10
+PDP10D = ${SIMHD}/PDP10
 PDP10 = ${PDP10D}/pdp10_fe.c ${PDP11D}/pdp11_dz.c ${PDP10D}/pdp10_cpu.c \
 	${PDP10D}/pdp10_ksio.c ${PDP10D}/pdp10_lp20.c ${PDP10D}/pdp10_mdfp.c \
 	${PDP10D}/pdp10_pag.c ${PDP10D}/pdp10_rp.c ${PDP10D}/pdp10_sys.c \
@@ -1523,7 +1526,7 @@ PDP10 = ${PDP10D}/pdp10_fe.c ${PDP11D}/pdp11_dz.c ${PDP10D}/pdp10_cpu.c \
 PDP10_OPT = -DVM_PDP10 -DUSE_INT64 -I ${PDP10D} -I ${PDP11D} ${NETWORK_OPT}
 
 
-PDP8D = PDP8
+PDP8D = ${SIMHD}/PDP8
 PDP8 = ${PDP8D}/pdp8_cpu.c ${PDP8D}/pdp8_clk.c ${PDP8D}/pdp8_df.c \
 	${PDP8D}/pdp8_dt.c ${PDP8D}/pdp8_lp.c ${PDP8D}/pdp8_mt.c \
 	${PDP8D}/pdp8_pt.c ${PDP8D}/pdp8_rf.c ${PDP8D}/pdp8_rk.c \
@@ -1533,7 +1536,7 @@ PDP8 = ${PDP8D}/pdp8_cpu.c ${PDP8D}/pdp8_clk.c ${PDP8D}/pdp8_df.c \
 PDP8_OPT = -I ${PDP8D}
 
 
-H316D = H316
+H316D = ${SIMHD}/H316
 H316 = ${H316D}/h316_stddev.c ${H316D}/h316_lp.c ${H316D}/h316_cpu.c \
 	${H316D}/h316_sys.c ${H316D}/h316_mt.c ${H316D}/h316_fhd.c \
 	${H316D}/h316_dp.c ${H316D}/h316_rtc.c ${H316D}/h316_imp.c \
@@ -1541,7 +1544,7 @@ H316 = ${H316D}/h316_stddev.c ${H316D}/h316_lp.c ${H316D}/h316_cpu.c \
 H316_OPT = -I ${H316D} -D VM_IMPTIP
 
 
-HP2100D = HP2100
+HP2100D = ${SIMHD}/HP2100
 HP2100 = ${HP2100D}/hp2100_stddev.c ${HP2100D}/hp2100_dp.c ${HP2100D}/hp2100_dq.c \
 	${HP2100D}/hp2100_dr.c ${HP2100D}/hp2100_lps.c ${HP2100D}/hp2100_ms.c \
 	${HP2100D}/hp2100_mt.c ${HP2100D}/hp2100_mux.c ${HP2100D}/hp2100_cpu.c \
@@ -1554,7 +1557,7 @@ HP2100 = ${HP2100D}/hp2100_stddev.c ${HP2100D}/hp2100_dp.c ${HP2100D}/hp2100_dq.
 	${HP2100D}/hp2100_di_da.c ${HP2100D}/hp2100_disclib.c
 HP2100_OPT = -DHAVE_INT64 -I ${HP2100D}
 
-HP3000D = HP3000
+HP3000D = ${SIMHD}/HP3000
 HP3000 = ${HP3000D}/hp_disclib.c ${HP3000D}/hp_tapelib.c ${HP3000D}/hp3000_atc.c \
 	${HP3000D}/hp3000_clk.c ${HP3000D}/hp3000_cpu.c ${HP3000D}/hp3000_cpu_base.c \
 	${HP3000D}/hp3000_cpu_fp.c ${HP3000D}/hp3000_cpu_cis.c ${HP3000D}/hp3000_ds.c \
@@ -1564,20 +1567,20 @@ HP3000 = ${HP3000D}/hp_disclib.c ${HP3000D}/hp_tapelib.c ${HP3000D}/hp3000_atc.c
 HP3000_OPT = -I ${HP3000D}
 
 
-I1401D = I1401
+I1401D = ${SIMHD}/I1401
 I1401 = ${I1401D}/i1401_lp.c ${I1401D}/i1401_cpu.c ${I1401D}/i1401_iq.c \
 	${I1401D}/i1401_cd.c ${I1401D}/i1401_mt.c ${I1401D}/i1401_dp.c \
 	${I1401D}/i1401_sys.c
 I1401_OPT = -I ${I1401D}
 
 
-I1620D = I1620
+I1620D = ${SIMHD}/I1620
 I1620 = ${I1620D}/i1620_cd.c ${I1620D}/i1620_dp.c ${I1620D}/i1620_pt.c \
 	${I1620D}/i1620_tty.c ${I1620D}/i1620_cpu.c ${I1620D}/i1620_lp.c \
 	${I1620D}/i1620_fp.c ${I1620D}/i1620_sys.c
 I1620_OPT = -I ${I1620D}
 
-I7000D = I7000
+I7000D = ${SIMHD}/I7000
 I7090 = ${I7000D}/i7090_cpu.c ${I7000D}/i7090_sys.c ${I7000D}/i7090_chan.c \
 	${I7000D}/i7090_cdr.c ${I7000D}/i7090_cdp.c ${I7000D}/i7090_lpr.c \
 	${I7000D}/i7000_chan.c ${I7000D}/i7000_mt.c ${I7000D}/i7090_drum.c \
@@ -1585,7 +1588,7 @@ I7090 = ${I7000D}/i7090_cpu.c ${I7000D}/i7090_sys.c ${I7000D}/i7090_chan.c \
 	${I7000D}/i7000_com.c ${I7000D}/i7000_ht.c 
 I7090_OPT = -I $(I7000D) -DUSE_INT64 -DI7090 -DUSE_SIM_CARD
 
-I7080D = I7000
+I7080D = ${SIMHD}/I7000
 I7080 = ${I7000D}/i7080_cpu.c ${I7000D}/i7080_sys.c ${I7000D}/i7080_chan.c \
 	${I7000D}/i7080_drum.c ${I7000D}/i7000_cdp.c ${I7000D}/i7000_cdr.c \
 	${I7000D}/i7000_con.c ${I7000D}/i7000_chan.c ${I7000D}/i7000_lpr.c \
@@ -1593,7 +1596,7 @@ I7080 = ${I7000D}/i7080_cpu.c ${I7000D}/i7080_sys.c ${I7000D}/i7080_chan.c \
 	${I7000D}/i7000_com.c ${I7000D}/i7000_ht.c 
 I7080_OPT = -I $(I7000D) -DI7080 -DUSE_SIM_CARD
 
-I7070D = I7000
+I7070D = ${SIMHD}/I7000
 I7070 = ${I7000D}/i7070_cpu.c ${I7000D}/i7070_sys.c ${I7000D}/i7070_chan.c \
 	${I7000D}/i7000_cdp.c ${I7000D}/i7000_cdr.c ${I7000D}/i7000_con.c \
 	${I7000D}/i7000_chan.c ${I7000D}/i7000_lpr.c ${I7000D}/i7000_mt.c \
@@ -1601,7 +1604,7 @@ I7070 = ${I7000D}/i7070_cpu.c ${I7000D}/i7070_sys.c ${I7000D}/i7070_chan.c \
 	${I7000D}/i7000_ht.c 
 I7070_OPT = -I $(I7000D) -DUSE_INT64 -DI7070 -DUSE_SIM_CARD
 
-I7010D = I7000
+I7010D = ${SIMHD}/I7000
 I7010 = ${I7000D}/i7010_cpu.c ${I7000D}/i7010_sys.c ${I7000D}/i7010_chan.c \
 	${I7000D}/i7000_cdp.c ${I7000D}/i7000_cdr.c ${I7000D}/i7000_con.c \
 	${I7000D}/i7000_chan.c ${I7000D}/i7000_lpr.c ${I7000D}/i7000_mt.c \
@@ -1609,21 +1612,21 @@ I7010 = ${I7000D}/i7010_cpu.c ${I7000D}/i7010_sys.c ${I7000D}/i7010_chan.c \
 	${I7000D}/i7000_ht.c 
 I7010_OPT = -I $(I7010D) -DI7010 -DUSE_SIM_CARD
 
-I704D  = I7000
+I704D  = ${SIMHD}/I7000
 I704   = ${I7000D}/i7090_cpu.c ${I7000D}/i7090_sys.c ${I7000D}/i7090_chan.c \
 	 ${I7000D}/i7090_cdr.c ${I7000D}/i7090_cdp.c ${I7000D}/i7090_lpr.c \
 	 ${I7000D}/i7000_mt.c ${I7000D}/i7090_drum.c ${I7000D}/i7000_chan.c 
 I704_OPT = -I $(I7000D) -DUSE_INT64 -DI704 -DUSE_SIM_CARD
 
 
-I701D  = I7000
+I701D  = ${SIMHD}/I7000
 I701   = ${I7000D}/i701_cpu.c ${I7000D}/i701_sys.c ${I7000D}/i701_chan.c \
 	 ${I7000D}/i7090_cdr.c ${I7000D}/i7090_cdp.c ${I7000D}/i7090_lpr.c \
 	 ${I7000D}/i7000_mt.c ${I7000D}/i7090_drum.c ${I7000D}/i7000_chan.c 
 I701_OPT = -I $(I7000D) -DUSE_INT64 -DI701 -DUSE_SIM_CARD
 
 
-I7094D = I7094
+I7094D = ${SIMHD}/I7094
 I7094 = ${I7094D}/i7094_cpu.c ${I7094D}/i7094_cpu1.c ${I7094D}/i7094_io.c \
 	${I7094D}/i7094_cd.c ${I7094D}/i7094_clk.c ${I7094D}/i7094_com.c \
 	${I7094D}/i7094_drm.c ${I7094D}/i7094_dsk.c ${I7094D}/i7094_sys.c \
@@ -1631,13 +1634,13 @@ I7094 = ${I7094D}/i7094_cpu.c ${I7094D}/i7094_cpu1.c ${I7094D}/i7094_io.c \
 I7094_OPT = -DUSE_INT64 -I ${I7094D}
 
 
-I650D = I650
+I650D = ${SIMHD}/I650
 I650 = ${I650D}/i650_cpu.c ${I650D}/i650_cdr.c ${I650D}/i650_cdp.c \
 	${I650D}/i650_sys.c
 I650_OPT = -I ${I650D} -DUSE_INT64 -DUSE_SIM_CARD
 
 
-IBM1130D = Ibm1130
+IBM1130D = ${SIMHD}/Ibm1130
 IBM1130 = ${IBM1130D}/ibm1130_cpu.c ${IBM1130D}/ibm1130_cr.c \
 	${IBM1130D}/ibm1130_disk.c ${IBM1130D}/ibm1130_stddev.c \
 	${IBM1130D}/ibm1130_sys.c ${IBM1130D}/ibm1130_gdu.c \
@@ -1651,7 +1654,7 @@ IBM1130_OPT += -DGUI_SUPPORT -lgdi32
 endif  
 
 
-ID16D = Interdata
+ID16D = ${SIMHD}/Interdata
 ID16 = ${ID16D}/id16_cpu.c ${ID16D}/id16_sys.c ${ID16D}/id_dp.c \
 	${ID16D}/id_fd.c ${ID16D}/id_fp.c ${ID16D}/id_idc.c ${ID16D}/id_io.c \
 	${ID16D}/id_lp.c ${ID16D}/id_mt.c ${ID16D}/id_pas.c ${ID16D}/id_pt.c \
@@ -1659,7 +1662,7 @@ ID16 = ${ID16D}/id16_cpu.c ${ID16D}/id16_sys.c ${ID16D}/id_dp.c \
 ID16_OPT = -I ${ID16D}
 
 
-ID32D = Interdata
+ID32D = ${SIMHD}/Interdata
 ID32 = ${ID32D}/id32_cpu.c ${ID32D}/id32_sys.c ${ID32D}/id_dp.c \
 	${ID32D}/id_fd.c ${ID32D}/id_fp.c ${ID32D}/id_idc.c ${ID32D}/id_io.c \
 	${ID32D}/id_lp.c ${ID32D}/id_mt.c ${ID32D}/id_pas.c ${ID32D}/id_pt.c \
@@ -1667,19 +1670,19 @@ ID32 = ${ID32D}/id32_cpu.c ${ID32D}/id32_sys.c ${ID32D}/id_dp.c \
 ID32_OPT = -I ${ID32D}
 
 
-S3D = S3
+S3D = ${SIMHD}/S3
 S3 = ${S3D}/s3_cd.c ${S3D}/s3_cpu.c ${S3D}/s3_disk.c ${S3D}/s3_lp.c \
 	${S3D}/s3_pkb.c ${S3D}/s3_sys.c
 S3_OPT = -I ${S3D}
 
 
-ALTAIRD = ALTAIR
+ALTAIRD = ${SIMHD}/ALTAIR
 ALTAIR = ${ALTAIRD}/altair_sio.c ${ALTAIRD}/altair_cpu.c ${ALTAIRD}/altair_dsk.c \
 	${ALTAIRD}/altair_sys.c
 ALTAIR_OPT = -I ${ALTAIRD}
 
 
-ALTAIRZ80D = AltairZ80
+ALTAIRZ80D = ${SIMHD}/AltairZ80
 ALTAIRZ80 = ${ALTAIRZ80D}/altairz80_cpu.c ${ALTAIRZ80D}/altairz80_cpu_nommu.c \
 	${ALTAIRZ80D}/altairz80_dsk.c ${ALTAIRZ80D}/disasm.c \
 	${ALTAIRZ80D}/altairz80_sio.c ${ALTAIRZ80D}/altairz80_sys.c \
@@ -1703,25 +1706,25 @@ ALTAIRZ80 = ${ALTAIRZ80D}/altairz80_cpu.c ${ALTAIRZ80D}/altairz80_cpu_nommu.c \
 ALTAIRZ80_OPT = -I ${ALTAIRZ80D} -DUSE_SIM_IMD
 
 
-GRID = GRI
+GRID = ${SIMHD}/GRI
 GRI = ${GRID}/gri_cpu.c ${GRID}/gri_stddev.c ${GRID}/gri_sys.c
 GRI_OPT = -I ${GRID}
 
 
-LGPD = LGP
+LGPD = ${SIMHD}/LGP
 LGP = ${LGPD}/lgp_cpu.c ${LGPD}/lgp_stddev.c ${LGPD}/lgp_sys.c
 LGP_OPT = -I ${LGPD}
 
 
-SDSD = SDS
+SDSD = ${SIMHD}/SDS
 SDS = ${SDSD}/sds_cpu.c ${SDSD}/sds_drm.c ${SDSD}/sds_dsk.c ${SDSD}/sds_io.c \
 	${SDSD}/sds_lp.c ${SDSD}/sds_mt.c ${SDSD}/sds_mux.c ${SDSD}/sds_rad.c \
 	${SDSD}/sds_stddev.c ${SDSD}/sds_sys.c
 SDS_OPT = -I ${SDSD}
 
 
-SWTP6800D = swtp6800/swtp6800
-SWTP6800C = swtp6800/common
+SWTP6800D = ${SIMHD}/swtp6800/swtp6800
+SWTP6800C = ${SIMHD}/swtp6800/common
 SWTP6800MP-A = ${SWTP6800C}/mp-a.c ${SWTP6800C}/m6800.c ${SWTP6800C}/m6810.c \
 	${SWTP6800C}/bootrom.c ${SWTP6800C}/dc-4.c ${SWTP6800C}/mp-s.c ${SWTP6800D}/mp-a_sys.c \
 	${SWTP6800C}/mp-b2.c ${SWTP6800C}/mp-8m.c
@@ -1730,7 +1733,7 @@ SWTP6800MP-A2 = ${SWTP6800C}/mp-a2.c ${SWTP6800C}/m6800.c ${SWTP6800C}/m6810.c \
 	${SWTP6800C}/mp-b2.c ${SWTP6800C}/mp-8m.c ${SWTP6800C}/i2716.c
 SWTP6800_OPT = -I ${SWTP6800D}
 
-INTELSYSD = Intel-Systems
+INTELSYSD = ${SIMHD}/Intel-Systems
 ISYS8010D = ${INTELSYSD}/isys8010
 ISYS8010C = ${INTELSYSD}/common
 ISYS8010 = ${ISYS8010C}/i8080.c ${ISYS8010D}/isys8010_sys.c \
@@ -1894,23 +1897,23 @@ SCELBI = ${SCELBIC}/i8008.c ${SCELBID}/scelbi_sys.c ${SCELBID}/scelbi_io.c
 SCELBI_OPT = -I ${SCELBID}
 
 
-TX0D = TX-0
+TX0D = ${SIMHD}/TX-0
 TX0 = ${TX0D}/tx0_cpu.c ${TX0D}/tx0_dpy.c ${TX0D}/tx0_stddev.c \
 	${TX0D}/tx0_sys.c ${TX0D}/tx0_sys_orig.c ${DISPLAYL}
 TX0_OPT = -I ${TX0D} $(DISPLAY_OPT)
 
 
-SSEMD = SSEM
+SSEMD = ${SIMHD}/SSEM
 SSEM = ${SSEMD}/ssem_cpu.c ${SSEMD}/ssem_sys.c
 SSEM_OPT = -I ${SSEMD}
 
-B5500D = B5500
+B5500D = ${SIMHD}/B5500
 B5500 = ${B5500D}/b5500_cpu.c ${B5500D}/b5500_io.c ${B5500D}/b5500_sys.c \
 	${B5500D}/b5500_dk.c ${B5500D}/b5500_mt.c ${B5500D}/b5500_urec.c \
 	${B5500D}/b5500_dr.c ${B5500D}/b5500_dtc.c
 B5500_OPT = -I.. -DUSE_INT64 -DB5500 -DUSE_SIM_CARD
 
-BESM6D = BESM6
+BESM6D = ${SIMHD}/BESM6
 BESM6 = ${BESM6D}/besm6_cpu.c ${BESM6D}/besm6_sys.c ${BESM6D}/besm6_mmu.c \
         ${BESM6D}/besm6_arith.c ${BESM6D}/besm6_disk.c ${BESM6D}/besm6_drum.c \
         ${BESM6D}/besm6_tty.c ${BESM6D}/besm6_panel.c ${BESM6D}/besm6_printer.c \
@@ -1980,7 +1983,7 @@ ifneq (,$(BESM6_BUILD))
     endif
 endif
 
-PDP6D = PDP10
+PDP6D = ${SIMHD}/PDP10
 ifneq (,$(DISPLAY_OPT))
   PDP6_DISPLAY_OPT = 
 endif
@@ -1991,7 +1994,7 @@ PDP6 = ${PDP6D}/kx10_cpu.c ${PDP6D}/kx10_sys.c ${PDP6D}/kx10_cty.c \
 	${PDP6D}/kx10_dpy.c ${DISPLAYL} $(DISPLAY340)
 PDP6_OPT = -DPDP6=1 -DUSE_INT64 -I $(PDP6D) -DUSE_SIM_CARD $(DISPLAY_OPT) $(PDP6_DISPLAY_OPT)
 
-KA10D = PDP10
+KA10D = ${SIMHD}/PDP10
 ifneq (,$(DISPLAY_OPT))
   KA10_DISPLAY_OPT = 
 endif
@@ -2016,7 +2019,7 @@ KA10 += ${KA10D}/ka10_lights.c
 KA10_LDFLAGS += -lusb-1.0
 endif
 
-KI10D = PDP10
+KI10D = ${SIMHD}/PDP10
 ifneq (,$(DISPLAY_OPT))
 KI10_DISPLAY_OPT = 
 endif
@@ -2035,7 +2038,7 @@ KI10 += ${KA10D}/ka10_lights.c
 KI10_LDFLAGS = -lusb-1.0
 endif
 
-ATT3B2D = 3B2
+ATT3B2D = ${SIMHD}/3B2
 ATT3B2 = ${ATT3B2D}/3b2_cpu.c ${ATT3B2D}/3b2_mmu.c \
 	${ATT3B2D}/3b2_iu.c ${ATT3B2D}/3b2_if.c \
 	${ATT3B2D}/3b2_id.c ${ATT3B2D}/3b2_dmac.c \
@@ -2049,7 +2052,7 @@ ATT3B2_OPT = -DUSE_INT64 -DUSE_ADDR64 -I ${ATT3B2D} ${NETWORK_OPT}
 ### Experimental simulators
 ###
 
-CDC1700D = CDC1700
+CDC1700D = ${SIMHD}/CDC1700
 CDC1700 = ${CDC1700D}/cdc1700_cpu.c ${CDC1700D}/cdc1700_dis.c \
         ${CDC1700D}/cdc1700_io.c ${CDC1700D}/cdc1700_sys.c \
         ${CDC1700D}/cdc1700_dev1.c ${CDC1700D}/cdc1700_mt.c \
@@ -2064,7 +2067,7 @@ CDC1700_OPT = -I ${CDC1700D}
 ### Unsupported/Incomplete simulators
 ###
 
-SIGMAD = sigma
+SIGMAD = ${SIMHD}/sigma
 SIGMA = ${SIGMAD}/sigma_cpu.c ${SIGMAD}/sigma_sys.c ${SIGMAD}/sigma_cis.c \
 	${SIGMAD}/sigma_coc.c ${SIGMAD}/sigma_dk.c ${SIGMAD}/sigma_dp.c \
 	${SIGMAD}/sigma_fp.c ${SIGMAD}/sigma_io.c ${SIGMAD}/sigma_lp.c \
@@ -2072,7 +2075,7 @@ SIGMA = ${SIGMAD}/sigma_cpu.c ${SIGMAD}/sigma_sys.c ${SIGMAD}/sigma_cis.c \
     ${SIGMAD}/sigma_rad.c ${SIGMAD}/sigma_rtc.c ${SIGMAD}/sigma_tt.c
 SIGMA_OPT = -I ${SIGMAD}
 
-ALPHAD = alpha
+ALPHAD = ${SIMHD}/alpha
 ALPHA = ${ALPHAD}/alpha_500au_syslist.c ${ALPHAD}/alpha_cpu.c \
     ${ALPHAD}/alpha_ev5_cons.c ${ALPHAD}/alpha_ev5_pal.c \
     ${ALPHAD}/alpha_ev5_tlb.c ${ALPHAD}/alpha_fpi.c \
@@ -2080,7 +2083,7 @@ ALPHA = ${ALPHAD}/alpha_500au_syslist.c ${ALPHAD}/alpha_cpu.c \
     ${ALPHAD}/alpha_mmu.c ${ALPHAD}/alpha_sys.c
 ALPHA_OPT = -I ${ALPHAD} -DUSE_ADDR64 -DUSE_INT64
 
-SAGED = SAGE
+SAGED = ${SIMHD}/SAGE
 SAGE = ${SAGED}/sage_cpu.c ${SAGED}/sage_sys.c ${SAGED}/sage_stddev.c \
     ${SAGED}/sage_cons.c ${SAGED}/sage_fd.c ${SAGED}/sage_lp.c \
     ${SAGED}/m68k_cpu.c ${SAGED}/m68k_mem.c ${SAGED}/m68k_scp.c \
@@ -2088,7 +2091,7 @@ SAGE = ${SAGED}/sage_cpu.c ${SAGED}/sage_sys.c ${SAGED}/sage_stddev.c \
     ${SAGED}/i8251.c ${SAGED}/i8253.c ${SAGED}/i8255.c ${SAGED}/i8259.c ${SAGED}/i8272.c 
 SAGE_OPT = -I ${SAGED} -DHAVE_INT64 -DUSE_SIM_IMD
 
-PDQ3D = PDQ-3
+PDQ3D = ${SIMHD}/PDQ-3
 PDQ3 = ${PDQ3D}/pdq3_cpu.c ${PDQ3D}/pdq3_sys.c ${PDQ3D}/pdq3_stddev.c \
     ${PDQ3D}/pdq3_mem.c ${PDQ3D}/pdq3_debug.c ${PDQ3D}/pdq3_fdc.c 
 PDQ3_OPT = -I ${PDQ3D} -DUSE_SIM_IMD
@@ -2098,7 +2101,7 @@ PDQ3_OPT = -I ${PDQ3D} -DUSE_SIM_IMD
 #
 ALL = pdp1 pdp4 pdp7 pdp8 pdp9 pdp15 pdp11 pdp10 \
 	vax microvax3900 microvax1 rtvax1000 microvax2 vax730 vax750 vax780 \
-	vax8200 vax8600 \
+	vax8200 vax8600 besm6 \
 	microvax2000 infoserver100 infoserver150vxt microvax3100 microvax3100e \
 	vaxstation3100m30 vaxstation3100m38 vaxstation3100m76 vaxstation4000m60 \
 	microvax3100m80 vaxstation4000vlc infoserver1000 \